JP2015171968A - Formation method of graphene-graphite film or composite film of nanocarbon and graphene-graphite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a formation method of a graphene-graphite film having mass-productivity and high quality, and at the same time having a low production cost and thick film thickness, or a composite film of nanocarbon and graphene-graphite.SOLUTION: An alloy including a typical element metal and a transition metal is brought into contact with a carbon source, carbon on the surface of the carbon source is dissolved in the alloy by heating the alloy, and a graphene-graphite film or a composite film of nanocarbon and graphene-graphite are deposited on the surface of the object brought into contact with the alloy by cooling the alloy.

Description

  The present invention relates to a method of forming a graphene / graphite film or a composite film of nanocarbon and graphene / graphite.

The carbon material is composed of an allotrope such as diamond composed of carbon having sp ³ hybrid orbitals, graphite (graphite) composed of carbon having sp ² hybrid orbitals, and calbin (polyyne) composed of carbon having sp hybrid orbitals, and a composite system thereof. Is an extremely diverse material. In recent years, nanocarbons such as sp ³ carbon-based nanodiamonds, sp ² carbon-based fullerenes, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanohorns, graphene, and graphene oxide have been named as new carbon materials.

Among these carbon materials, it has been used for a relatively long time in industry, and the largest and most widely used is mainly sp ² system such as glassy carbon, carbon fiber, carbon fiber reinforced carbon composite material, etc. It is a carbon material. These sp ² -based carbon materials are light because the specific gravity is usually smaller than that of metals, and have a relatively high Mohs hardness of 7, so that they have a considerable hardness, are chemically stable, are inert to living organisms, and are resistant to heat at about 1000 ° C. It has the features of maintaining practical strength up to a high temperature exceeding 1, and withstanding repeated use.

However, the current sp ² carbon material is essentially incompletely graphitized due to limitations in existing manufacturing methods. Their surfaces are covered with a large number of grain boundaries of several nanometers to several micrometers, and each crystal has a large number of defect structures such as atomic defects. These grain boundaries and defect structures can be the starting point for physical erosion such as air friction and sputtering, and chemical corrosion such as oxidation. For this reason, the surface of the sp ² -based carbon material having a large number of grain boundaries and defect structures is significantly inferior in wear resistance and oxidation resistance as compared with a completely crystalline graphite surface. Moreover, due to structural imperfections of the surface of the sp ² carbon material, the gas barrier performance of the sp ² carbon material is also a problem that becomes limiting. Furthermore, due to the above-mentioned problems, it is pointed out that when products made of sp ² carbon material manufactured by existing technology are used under severe conditions, their lifetime is shorter than required. Has been.

With the development of technology in recent years, several methods for coating the surface of the sp ² -based carbon material have been put into practical use for the purpose of reducing the above problems. For example, Japanese Patent No. 3228489 (Patent Document 1) discloses a technique for coating with a surface-treated silicon carbide (SiC) layer. Also disclosed is a technique of applying a graphite coating on the surface of an sp ² carbon material by a CVD (Chemical Vapor Deposition) method. For example, JP-A-2000-351689 (Patent Document 2) discloses a coating technique for reinforcing a crucible surface produced from a carbon fiber-reinforced carbon composite material with pyrolytic carbon, and JP-A-2003-18076 (Patent Document 3). Discloses a coating technique with carbon derived from thermal CVD for improving the gas barrier property of sp ² carbon material.

  Furthermore, a method for producing a graphene film on a carbon material or an insulator substrate by using gallium has been reported. For example, Japanese Patent No. 4970619 (Patent Document 4) discloses a technique for producing a graphene film at an interface between gallium and amorphous carbon. PCT / JP2011 / 075883 (Patent Document 5) and PCT / JP2011 / 0777879 (Patent Document 6) each disclose a technique of directly forming a graphene film on the surface of a carbide and an insulator. According to the techniques of Patent Documents 5 and 6, since high-quality graphene can be formed on various material surfaces, a graphene substrate for device fabrication can be realized.

Japanese Patent No. 3228489 (page 3-4, FIG. 3) JP 2000-351689 A (page 2-4) JP 2003-183076 A (page 2-3) Japanese Patent No. 4970619 (page 3-4, FIG. 4) WO2012 / 060468 (6th page, FIG. 1) WO2012 / 086387 (6th page, FIG. 1)

  However, the coating techniques disclosed in Patent Documents 1 to 6 have several problems.

First, the coating of the sp ² carbon material with the SiC layer disclosed in Patent Document 1 has a problem that the conductivity of the sp ² carbon material is lost. This is because SiC is a wide gap semiconductor and is electrically semi-insulating. This is a fatal defect when using the sp ² carbon material as an electrode.

Second, in Patent Document 2, CVD is performed on the surface of the sp ² -based carbon material with pyrolytic carbon using methane gas as a raw material for a long time of at least 50 hours and a growth temperature of 1800 ° C. Processing is required. Therefore, this technique causes the problem that the apparatus cost and the material cost increase, and there are many problems from the viewpoint of resource saving and energy saving. Further, it is generally known that in the CVD method using hydrocarbon as a raw material, graphitization does not proceed without a metal catalyst such as copper or nickel. That is, the pyrolytic carbon film disclosed in Patent Document 2 is not carbonaceous crystalline but amorphous carbon. Therefore, it is impossible to expect wear resistance and oxidation resistance by this coating technique.

  Third, Patent Document 3 requires CVD under severe conditions such as high temperature of 1200 ° C. or higher, hydrocarbon gas as a raw material, hydrogen gas as a carrier gas, and hydrogen chloride gas inflow for coating. Is done. Moreover, high temperature of 2000-3000 degreeC is required for final graphitization of a coating layer. Therefore, like the problem in Patent Document 2, this technique causes a problem that the apparatus cost and the material cost increase, and there are many problems from the viewpoint of resource saving and energy saving. In addition, the use of dangerous gases such as hydrogen and hydrogen chloride is likely to have adverse health and environmental impacts.

  Fourth, the problem of Patent Document 4 is that only a few layers of graphene film, that is, an ultrathin graphite film having a thickness of several nanometers at the maximum can be formed at the interface between gallium and amorphous carbon. It is not. This problem is caused by the fact that only the extreme surface layer of amorphous carbon can be converted into graphene because Patent Document 4 uses an interfacial reaction between gallium and amorphous carbon. Therefore, it is impossible to cover with a graphene film having 100 or more layers, that is, a graphite film having a film thickness of several tens of nanometers or more.

  Fifth, the graphene film forming techniques disclosed in Patent Documents 5 and 6 have a problem that it is difficult in principle that the film thickness of the graphite film exceeds 100 nm. This problem is caused by the liquid phase in which the graphene film forming technique of Patent Documents 5 and 6 dissolves a carbon material as a raw material in liquid gallium at the time of heating, and deposits carbon dissolved in the liquid gallium at the time of cooling on the target material surface. Although it is based on the growth method, the solubility of carbon in gallium is only 30 atomic ppm (parts per million atomic) even at a high temperature of 900 ° C., which is due to extremely low carbon solubility. In the first place, in Patent Documents 5 and 6, it is a technical point of graphene film formation that positively utilizes such characteristics that the carbon solubility of gallium is negligible. This is because excess carbon inhibits the formation of an ultrathin graphene film. Therefore, the graphene production techniques of Patent Documents 5 and 6 are suitable for providing a high-quality graphene substrate for devices, but are not suitable for providing a strong and thick high-quality graphite film.

  Sixth, there is a problem that a composite film of nanocarbon and graphene / graphite cannot be formed on the object to be coated with any of the techniques disclosed in Patent Documents 1 to 6. This problem is caused by the fact that it is impossible to fuse nanocarbon and graphene / graphite via a carbon-carbon covalent bond with existing methods.

As described above, the coating techniques of Patent Documents 1 to 6 have various problems. In particular, in the above-described technique, it is extremely difficult to simultaneously achieve complete crystallization and thickening due to the graphite structure in the coating layer on the surface of the sp ² -based carbon material. It is impossible to form a composite film of carbon and graphene / graphite. Therefore, a means for solving the above problems has been desired.

  The present invention has been made in view of the above problems, and its object is to provide a mass-produced and high-quality graphene / graphite film having a low production cost and a large film thickness, or nanocarbon and graphene It is an object of the present invention to provide an object coated with a composite film of graphite and a method for manufacturing the same.

In the present invention, (a) an alloy containing a typical element metal and a transition metal is brought into contact with a carbon source, and the alloy is heated to dissolve carbon on the surface of the carbon source in the alloy,
(B) By cooling the alloy, a graphene / graphite film or a composite film of nanocarbon and graphene / graphite is deposited on the surface of an object in contact with the alloy.
This is a method for forming a graphene / graphite film or a composite film of nanocarbon and graphene / graphite.

  According to the present invention, mass production, high quality, low production cost, and low-cost production of a graphene / graphite film with a large film thickness or a composite film of nanocarbon and graphene / graphite are used to coat the material surface. It is possible to provide a method.

It is a perspective view which shows the principle of the graphene graphite film formation by the liquid phase growth method used by this invention. It is a figure showing the carbon solubility curve in a typical element metal (gallium) and a transition metal (nickel). It is a gallium-iron binary system phase diagram showing the relationship between the ratio region where the gallium-iron alloy flux works effectively and the temperature region. It is a gallium-cobalt binary phase diagram showing the relationship between the ratio region where the gallium-cobalt alloy flux works effectively and the temperature region. FIG. 5 is a typical element metal (gallium) -transition metal (nickel) binary phase diagram showing a relationship between a ratio region where a typical element metal (gallium) / transition metal (nickel) alloy flux effectively works and a temperature region. It is a perspective view which shows the process of the manufacturing method of a present Example. It is a figure which shows the optical microscope image of the carbon fiber reinforced carbon composite material to which the liquid phase growth method using a gallium simple substance and steel (SUS304) simple substance as a flux was applied. It is a figure which shows the optical microscope image of the graphene * graphite film covering carbon fiber reinforced carbon composite material explaining the minimum of the ratio which a typical element metal (gallium) and transition metal (nickel) alloy flux works effectively. It is a figure which shows the optical microscope image of the graphene * graphite film covering carbon fiber reinforced carbon composite material and carbon fiber reinforced carbon composite material explaining the upper limit of the ratio which a gallium and iron alloy flux works effectively. It is a figure which shows the optical microscope image of the graphene * graphite film coating | cover carbon fiber reinforced carbon composite material and carbon fiber reinforced carbon composite material explaining the upper limit of the ratio which a gallium-cobalt alloy flux works effectively. It is the figure which shows the optical microscope image of the graphene-graphite film coating carbon fiber reinforced carbon composite and carbon fiber reinforced carbon composite explaining the upper limit of the ratio at which the typical element metal (gallium) / transition metal (nickel) alloy flux works effectively is there. It is a figure which shows the optical microscope image of the carbon fiber reinforced carbon composite material coat | covered with the composite film of various nanocarbon and a graphene graphite. It is a figure which shows the optical microscope image of various heat-resistant materials coat | covered with the composite film of the single-walled nanotube carbon and graphene graphite.

(Description of configuration)
Next, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to a following example, In the range which does not deviate from the meaning of this invention, it can change arbitrarily and can implement.

  First, the principle used in this embodiment will be described.

In the present embodiment, an alloy flux containing a typical element metal and a transition metal is used in the liquid phase growth of graphenization or graphitization.
By alloying, the added transition metal increases the carbon solubility, and the added typical element metal prevents the alloy flux and the object to be coated from sticking, while suppressing the formation of transition metal carbide, thereby reducing the film thickness. For example, it is possible to increase the thickness of a graphene / graphite film or a composite film of nanocarbon and graphene / graphite, such as 100 nm or more.

  FIG. 1 is a perspective view showing the principle of a manufacturing method for covering a target material surface with a graphene / graphite film as an embodiment of the present invention.

  In the present invention, a liquid phase growth method is used as a means for growing graphene / graphite. The principle of the liquid phase growth method is that the carbon material is once dissolved as carbon in the metal used as a flux (high temperature solvent) by heating, and then the carbon dissolved in the metal is cooled on the surface of the graphene film by cooling. Alternatively, it is deposited as a graphite film.

  The principle of forming a graphene / graphite film by the liquid phase growth method can be explained in three stages shown in FIG.

As shown in FIG. 1A, the first stage is a stage in which the carbon source 1, the flux 2, and the covering object 3 are prepared, and the carbon source 1 and the covering object 3 are arranged with the flux 2 interposed therebetween. . At this time, in the existing method, gallium (Ga) is mainly used as the flux 2.
There are two main reasons for using gallium. The first reason is that the melting point of gallium is 29.6 ° C., which is near room temperature, so that the arrangement and removal of gallium is easy before and after production, and the second reason is that the boiling point of gallium is as high as 2403 ° C. This is because the temperature range in the liquid state is wide and the temperature range that can be used as the flux for liquid phase growth is wide.

  The second stage is a stage in which the carbon 4 existing in the surface layer of the carbon source 1 is dissolved in the flux 2 by heating at an appropriate temperature, as shown in FIG. The amount of carbon 4 dissolved in the flux 2, that is, the carbon solubility in the flux 2, depends on the metal type of the flux 2 used and the heating temperature.

  In the third stage, as shown in FIG. 1C, by cooling, the carbon 4 dissolved in the flux 2 becomes supersaturated and starts to precipitate on the surface layer of the flux 2, resulting in the carbon source 1 and the object to be coated. In this stage, a graphene / graphite film 5 is formed on the surface of the object 3.

  In view of the principle of the liquid phase growth method described above, the following two methods are usually conceivable in order to increase the thickness of the graphene / graphite film. That is, the first method is to raise the heating temperature as much as possible in the second stage, and the second method is to select a metal having high carbon solubility as the flux 2. However, as explained below, detailed experiments have shown that these two methods alone are insufficient.

First, the problem with the first method, that is, the heating temperature rise, is that when gallium is used as the flux 2, the upper limit of the heating temperature is around 1500 ° C. Since the vapor pressure of gallium exceeds 10 ³ Pa at 1500 ° C., the consumption of gallium is severe at this temperature, and as the heating time elapses, it is no longer used as a flux. As will be described in detail in Example 1, as shown in FIG. 7 (c), the film thickness of the graphene / graphite film on the coating target 3 obtained by liquid phase growth with a gallium flux heated at an upper limit temperature of 1500 ° C. is at most 25 nm. It is. Moreover, since gallium to be evaporated must be estimated and added in excess, it is not practical in view of manufacturing costs.
Therefore, it is not possible to increase the thickness of the graphene / graphite film to 100 nm or more by simply increasing the heating temperature.

  Next, the second method, that is, the problem of selecting a metal having a high carbon solubility as a flux, is two points of fixation to the surface of the coating object 3 and carbide formation. For example, comparing nickel (Ni), which is a transition metal, with gallium, which is a typical element metal, as shown in FIG. 2, the carbon solubility of nickel is 2-3 orders of magnitude higher than that of gallium at any temperature. This tendency is the same for other transition metals. Therefore, it can be inferred that if the flux 2 in the liquid phase growth is replaced from gallium to a transition metal, the thickness can be increased by an order of magnitude.

  However, experiments have shown that this method does not actually work. For example, as shown in FIG. 7 (d), when steel (SUS304) is used as a flux, after cooling, the flux 2 firmly adheres to the surface of the covering object 3 and does not peel off naturally. Although details will be described in Example 1, even if the fixed flux is dissolved with an acid, the formation of a graphene / graphite film is not observed on the surface of the object 3 to be coated, and only a rough surface remains.

The cause of the sticking is that the surface of the coating object 3 is SUS304 itself having poor peelability or a carbide (Fe ₃ C or the like) in which the dissolved carbon 4 and the constituent elements of SUS304, such as metal 2, such as iron are combined in the cooling process. This is thought to be due to precipitation. Further, the reason why the graphene / graphite film is not formed is that the carbon 4 dissolved in the metal 2 is not as pure carbon graphite but as a carbide (Fe ₃ C, etc.) combined with the flux 2 in the cooling process. This is presumably because it precipitates on the surface of 3 or the inside of the flux 2.

  Therefore, in order to achieve thickening of the graphene / graphite film, it is not sufficient to simply select a metal with high carbon solubility as a flux, to suppress carbide formation in the cooling process, It is necessary to ensure the peelability of the flux 2.

As a means to solve the above problem, as a result of earnest research and development, an alloy of transition metal such as iron, cobalt, nickel and typical element metal such as gallium should be used as a flux for liquid phase growth of graphene / graphite film. It was clarified that is effective. This effect is a complementary and synergistic effect obtained by alloying the transition metal and the typical element metal, and the presence of both solves the above-described problems. That is, the alloy flux has three effects. The first effect is that the presence of the transition metal suppresses an increase in the vapor pressure of the typical element metal at a high temperature. Thereby, an increase in heating temperature can be expected.
The second effect is that the presence of the typical element metal suppresses transition metal carbide formation in the cooling process. The third effect is that when the flux is removed, the presence of a typical element metal alone or a metal compound of a typical element metal and a transition metal (such as Ga ₃ Ni) improves the peelability and prevents the flux from adhering to the material surface. These three effects are successful, and it is possible to achieve a thick film having a graphene / graphite film thickness of 100 nm or more. For the formation and thickening of the graphene / graphite film, it is desirable to precisely adjust the ratio of the typical element metal to the transition metal in the alloy flux and to set the heating temperature appropriately. The above discussion also applies to composite films of nanocarbon and graphene / graphite.

  Below, the ratio of the ratio of the typical element metal to the transition metal in the alloy flux used for the formation of the graphene / graphite film and the thickening of the film with a film thickness of 100 nm or more and the range of the heating temperature, the typical element metal is gallium, transition metal As an example, iron, nickel, and cobalt will be described based on the binary phase diagrams of the two.

  FIG. 3 is a gallium-iron binary phase diagram. The vertical axis represents temperature (° C.), the horizontal axis (upper) represents the weight ratio (% by weight) of iron, and the horizontal axis (lower) represents the atomic ratio (atomic%) of iron.

  Conditions for increasing the thickness of the graphene / graphite film on the material (film thickness: 100 nm or more): Z is the logical product (A∩B∩C) of the following three conditions (A, B, C). That is, Z = A∩B∩C.

Condition A: Temperature condition for alloy liquefaction Condition B: Temperature condition for graphene / graphite film formation Condition C: Alloy ratio condition for effective alloy flux for thickening Condition A is a typical element metal And the lower limit of the temperature at which the transition metal alloy flux becomes liquid. In the gallium-iron binary phase diagram of FIG. 3, the liquid phase from the melting point of gallium: 29.8 ° C. to the melting point of iron: 1538 ° C. The temperature range is higher than the line (see legend in FIG. 3). This condition is derived from the fact that the liquid phase growth method is used in the present invention, and the alloy flux plays a role in the liquid state.

  Condition B defines the lower limit of the heating temperature at which a graphite structure is formed instead of amorphous carbon in liquid phase growth, and is a temperature range of 800 ° C. or higher (see legend in FIG. 3). This condition is derived from the fact that the growth temperature of graphene / graphite is at least around 800 ° C. in the liquid phase growth method.

Condition C is the logical product (C ₁ ∩C ₂ ∩C ₃ ) of the following three conditions (C ₁ , C ₂ , C ₃ ). That is, C = C ₁ ∩C ₂ ∩C ₃ .

Conditions C _1, the carbon dissolved in the typical element metal and alloys in the flux of the transition metal during heating to define the upper limit of the transition metal ratios not precipitate as carbides combined with a transition metal during cooling. As described in Example 3, in the case of a gallium / iron alloy flux, this upper limit is 50% by weight (about 62 atomic%).

Condition C ₂ are peelable by typical elemental metal additive defines the upper limit of the transition metal ratio in the alloy flux is assured. As described in Example 3, in the case of a gallium / iron alloy flux, this upper limit is 20% by weight (about 25 atomic%).

Condition C ₃ defines the lower limit of the transition metal ratio in the alloy flux thickness of graphene graphite film becomes remarkable effect of transition metal additives with the above 100 nm. As explained in Example 3, the lower limit is 1% by weight.

As described above, the condition C is obtained by calculating the logical product of the conditions C ₁ , C ₂ , and C ₃ . In the case of a gallium-iron alloy flux, the range of the condition C, that is, the iron ratio is 1 to 20% by weight (about 1.2 to 25 atomic%) (see legend in FIG. 3). As will be described in Examples 2 to 5 described later, the condition C is obtained through experiments.

  The above is the condition Z required for the region satisfying all three conditions A, B, and C, that is, the condition for increasing the thickness of the graphene / graphite film (film thickness: 100 nm or more).

  In the case of a gallium / iron alloy flux, the condition Z for increasing the thickness of the graphene / graphite film on the material (film thickness: 100 nm or more): Z is a region surrounded by a dotted line in FIG. That is, the approximate temperature range is 800 ° C. or higher, and the ratio of iron in the alloy flux is 1 wt% to 20 wt% (about 1.2 to 25 atomic%).

  FIG. 4 is a gallium-cobalt binary phase diagram. The legend and the like are the same as in FIG. In the case of gallium-cobalt alloy flux, the same argument holds as in the case of the above-described gallium-iron alloy flux.

  In the case of a gallium-cobalt alloy flux, the condition for increasing the thickness of the graphene / graphite film on the material (film thickness: 100 nm or more): Z is a region surrounded by a dotted line in FIG. That is, the approximate temperature range is 800 ° C. or more, and the ratio of cobalt in the alloy flux is 1 to 30% by weight (about 1.2 to 35 atomic%).

  FIG. 5 is a gallium-nickel binary phase diagram. The legend and the like are the same as in FIG. In the case of gallium-cobalt alloy flux, the same argument holds as in the case of the above-described gallium-iron alloy flux.

  In the case of a gallium-nickel alloy flux, the condition Z for increasing the thickness of the graphene / graphite film on the material (film thickness: 100 nm or more): Z is a region surrounded by a dotted line in FIG. That is, the approximate temperature range is 800 ° C. or higher, and the ratio of nickel in the alloy flux is 1 to 40% by weight (about 1.2 to 48 atomic%).

  In addition, in other typical element metal / transition metal alloy fluxes, no transition metal ratio having a lower limit of less than 1% by weight and an upper limit of more than 40% by weight was not found. Therefore, these numbers are general.

  In summary, the temperature range is 800 ° C. or higher, and the lower limit of the transition metal ratio in the typical element metal / transition metal alloy flux is 1% by weight, and the upper limit is 40% by weight.

  Next, the manufacturing method of this embodiment will be described.

  FIG. 6 is a schematic view showing a manufacturing method for coating the surface of a target structure with a graphene film / graphite film or a composite film of nanocarbon and graphene / graphite film as an embodiment of the present invention.

  As a first step, a carbon source carrier 11 is prepared as shown in FIG.

  The carbon source support 11 has a function of supporting a carbon source which is a raw material for manufacturing a graphene / graphite film or a composite film of nanocarbon and graphene / graphite film. However, the carbon source carrier 11 is not necessarily required when the carbon source is solid and can be self-supported.

  The carbon source support 11 can be selected from heat-resistant materials, and at least one selected from the following five groups is selected.

  The first group of materials of the carbon source carrier 11 are quartz (SiO2), alumina and sapphire (Al2O3), titanium oxide (TiO2), zinc oxide (ZnO), magnesium oxide (MgO), nickel oxide (NiO), and zirconia. It is an oxide such as (ZrO2), lithium niobate (LiNbO3), or lithium tantalate (LiTaO3).

  The second group of materials are nitrides such as boron nitride (BN), aluminum nitride (AlN), gallium nitride (GaN), carbon nitride (C3N4), and carbon boron nitride (BCN).

  The third group of materials are silicon carbide (SiC), boron carbide (B4C), aluminum carbide (Al4C3), titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), carbonized Carbides such as niobium (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), and tungsten carbide (WC).

  The fourth group of materials is a fluoride such as barium fluoride (BaF2), calcium fluoride (CaF2), and magnesium fluoride (MgF2).

  The fifth group of materials are other heat-resistant materials such as mica (mica) and diamond.

  As a second step, a carbon source 12 is disposed on the surface of the carbon source carrier 11 as shown in FIG.

  The carbon source 12 serves as a raw material for forming a graphite structure.

  As the carbon source 12, any substance that basically contains carbon can be used, and at least one selected from the following six groups is selected.

  The first group of materials of the carbon source 12 are carbon materials such as amorphous carbon, glassy carbon, crystalline graphite, diamond, carbon fiber, and carbon fiber reinforced carbon composite material.

Material of the second group, Calvin, single-walled nanotubes, multi-walled carbon nanotubes, fullerenes typified by C ₆₀ and C _70, nanodiamond, graphene, carbon nanohorn, a nanocarbon material such as graphene oxide.

  The third group of materials are low molecular organic compounds such as metallocene, naphthalene, anthracene, and pentacene.

  The fourth group of materials are artificial high molecular organic compounds such as Teflon (registered trademark), PMMA (polymethyl methacrylate), and polyethylene.

  The fifth group of materials are natural high molecular organic compounds such as proteins, nucleic acids, lipids and polysaccharides.

The sixth group of materials are silicon carbide (SiC), boron carbide (B ₄ C), aluminum carbide (Al ₄ C ₃ ), titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide. (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), tungsten carbide (WC), carbon nitride (C ₃ N ₄ ), carbon boron nitride (BCN), etc. It is an inorganic compound containing carbon.

  As a method for arranging the carbon source 12, the following three methods can be used as appropriate.

  The first arrangement method of the carbon source 12 is a dry film forming method such as a vacuum vapor deposition method, a molecular beam vapor deposition method, an ion plating method, an ion beam vapor deposition method, a chemical vapor deposition method, or a sputtering method. The second arrangement method is a wet film forming method such as a dropping method, a spin coating method, or a dip coating method. The third arrangement method is a spray coating method, an air spray coating method, an electrodeposition coating method, an electrostatic coating method, or the like.

  As a third step, an alloy flux 13 is disposed on the carbon source 12 as shown in FIG.

  As described above, the alloy flux 13 serves as a flux (high temperature solvent) that dissolves carbon constituting the carbon source 12 during heating and precipitates the dissolved carbon as a graphite structure during cooling.

  As the alloy flux 13, an alloy of the following typical element metal and transition metal is used.

  Typical element metals added to the alloy flux 13 include typical elements such as gallium (Ga), indium (In), tin (Sn), aluminum (Al), thallium (Tl), lead (Pb), and bismuth (Bi). At least one selected from the group of metals is selected.

  As transition metals to be added to the alloy flux 13, scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni) , Copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag) , Cadmium (Cd), lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au) , At least one selected from the group of transition metals such as mercury (Hg).

  In the above, gallium is particularly preferable as the typical element metal, and iron, nickel, and cobalt are preferable as the constituent components of the alloy flux as the transition metal. The reason why gallium is preferred is to suppress the formation of transition metal carbide because gallium improves the peelability when the alloy flux is removed from the material surface. The reason why iron, nickel, and cobalt are preferable is that the solubility of carbon as a raw material for graphene / graphite is remarkably high.

  As a fourth step, a structure 14 is disposed on the alloy flux 13 as shown in FIG.

  The structure 14 is a target object that covers a graphene / graphite film or a composite film of nanocarbon and graphene / graphite film. The structure 14 can have any shape from micro to macro, and may have a wire-like one-dimensional structure, a sheet-like two-dimensional structure, and various shapes of three-dimensional structures. The structure 14 can be selected from heat-resistant materials, and at least one selected from the following seven groups is selected.

  The first group of the structures 14 is a carbon material such as amorphous carbon, glassy carbon, crystalline graphite, diamond, carbon fiber, or carbon fiber reinforced carbon composite material.

  The second group of materials are nanocarbon materials such as carbine, single-walled nanotubes, multi-walled carbon nanotubes, fullerenes typified by C60 and C70, nanodiamonds, graphene, carbon nanohorns, and graphene oxide.

  The third group consists of quartz (SiO2), alumina and sapphire (Al2O3), titanium oxide (TiO2), zinc oxide (ZnO), magnesium oxide (MgO), nickel oxide (NiO), zirconia (ZrO2), lithium niobate ( It is an oxide such as LiNbO3) or lithium tantalate (LiTaO3).

  The fourth group includes nitrides such as boron nitride (BN), aluminum nitride (AlN), gallium nitride (GaN), carbon nitride (C3N4), and carbon boron nitride (BCN).

  The fifth group is silicon carbide (SiC), boron carbide (B4C), aluminum carbide (Al4C3), titanium carbide (TiC), and zirconium carbide (ZrC). These are carbides such as hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), and tungsten carbide (WC).

  The sixth group is a fluoride such as barium fluoride (BaF2), calcium fluoride (CaF2), and magnesium fluoride (MgF2).

  The seventh group is other heat-resistant materials such as mica (mica) and diamond.

  In addition, when the structure 14 is other than the second group and the structure 14 is covered with a composite film of nanocarbon and graphene / graphite, the nanocarbon is formed on the surface of the structure 14 in advance. It is good to leave. The nanocarbon thus formed serves as a nanocarbon source of a composite film of nanocarbon and graphene / graphite, and also as a carbon source.

  As the nanocarbon material, at least one selected from carbyne, single-walled nanotubes, multi-walled carbon nanotubes, fullerenes represented by C60 and C70, nanodiamonds, graphene, carbon nanohorns, graphene oxide, and the like is selected.

  As a fifth step, heat treatment is performed.

At this time, the carbon source carrier 11, the carbon source 12, the alloy flux 13, and the structure 14 are accommodated in a container with an appropriate lid.
This is to prevent the flux and transpiration of the alloy flux 13 during heating. When heating to an appropriate temperature, the alloy flux 13 is melted, and the carbon contained in the carbon source 12 is dissolved in the alloy flux 13. When the structure 14 is formed of nanocarbon, part of the carbon constituting the nanocarbon is also dissolved in the alloy flux 13.

    As means for heating, the following three methods can be appropriately used.

  The first heating method is a heating method using an electric furnace or an infrared lamp. The second heating method is a heating method using a high frequency induction heating device. The third heating method is a heating method using a microwave dielectric heating device.

  The heating temperature is 800 ° C. or higher.

  As described above, the heating temperature is determined from both the temperature condition (condition A) for liquefying the alloy and the temperature condition (condition B) for forming graphene / graphite.

  As a sixth step, a cooling process is performed.

  When cooling is performed, carbon dissolved in the alloy flux 13 is deposited on the surface of the structure 14 as graphene / graphite. In addition, when the structure 14 is comprised with nanocarbon, or when the structure 14 is surface-coated with nanocarbon, reconstruction of nanocarbon by dissolved carbon and graphene / graphite production proceed in concert. Thus, a composite film in which nanocarbon and graphene / graphite are fused via a strong covalent bond is formed. The film 14 is covered with these films.

  The conditions for the cooling treatment are as follows.

  The lower the temperature drop per unit time, that is, the cooling rate, the higher the quality of graphene graphite. For example, in the range from the heated temperature to 400 ° C., 100 ° C./min or less is desirable, 10 ° C./min or less is more desirable, and 1 ° C./min or less is even more desirable. In addition, at 400 degrees C or less, the cooling by natural heat radiation may be sufficient.

  Here, the upper limit of the cooling rate of 100 ° C./min or less is the maximum rate allowed to prevent the dissolved carbon in the alloy flux 13 from being precipitated as amorphous. The quality of graphene and graphite can be quantified using the D / G ratio, which is the intensity ratio of the D band and G band appearing in the Raman spectrum, as the index. The lower the D / G ratio, the higher the quality of graphene / graphite. For example, when the cooling rate is 10 ° C./min or less, it is possible to form high-quality graphene graphite having a D / G ratio ≦ 0.2. Furthermore, when the cooling rate is 1 ° C./min or less, it is possible to obtain a particularly high quality graphene graphite having a D / G ratio ≦ 0.1.

  As a seventh step, the alloy flux is removed.

  After cooling, the alloy flux 13 is in a liquid or solid state depending on the alloy ratio. In the case of liquid, most is removed by physical suction. If it is solid, it will peel off naturally. If there is a residue 15 of the alloy flux 13 as shown in FIG. 6E, it is chemically dissolved and removed by acid / alkali treatment.

As an acid for dissolving the residue of the alloy flux 13, hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), or the like can be used. When the metal 2 is an amphoteric metal such as gallium or aluminum, an aqueous solution of sodium hydroxide (NaOH), potassium hydroxide (KOH), or tetramethylammonium hydroxide can be used. The cleaning effect is high when the whole is immersed in a cleaning solution under appropriate heating.

  The used alloy flux 13 can be reused as a flux. The regeneration of the flux has the effect of significantly reducing the manufacturing cost.

  Through the above steps, as shown in FIG. 6F, a structure 17 is finally obtained which is covered with a graphene / graphite film or a composite film 16 of nanocarbon and graphene / graphite.

This embodiment has the following effects. The first effect is that by using a liquid phase growth method using an alloy flux containing a typical element metal and a transition metal, the graphene is free of impurities, has no structural defects, and is controlled to have a film thickness of 100 nm or more. An object can be provided that has been coated with a graphite film or a composite film of nanocarbon and graphene / graphite. In particular, complete crystallization and thickening due to the graphite structure can be simultaneously achieved on the surface of the sp ² -based carbon material.

The second effect is that by using a liquid phase growth method using an alloy flux containing a typical element metal and a transition metal, the film thickness of an object having an arbitrary shape that realizes low manufacturing cost, energy saving, and low environmental load is achieved. A manufacturing method for coating a graphene / graphite film of 100 nm or more, or a composite film of nanocarbon and graphene / graphite can be provided.
(Example)
Hereinafter, based on an Example and a comparative example, this invention is demonstrated in detail.
(Comparative example)
In this comparative example, liquid phase growth using only gallium is used to prove that a film of graphene / graphite film having a film thickness of 100 nm or more cannot be expected even if liquid phase growth is attempted using only a typical element metal as a flux. Will be described. Next, steel (SUS304) is used for the purpose of demonstrating that it is impossible to form a graphene-graphite film even if a liquid phase growth is attempted using only a transition metal having a significantly higher carbon solubility as a flux than gallium. The liquid phase growth used will be described.

  Manufacture was performed according to the steps of the manufacturing method shown in FIG.

As a first procedure, two carbon fiber reinforced carbon composite material substrates were prepared as carbon sources / covering objects.
The surface of the carbon fiber reinforced carbon composite material substrate was polished. The reason for polishing is to quantitatively evaluate the change before and after application of the liquid phase growth method by eliminating the unevenness originally existing on the substrate. The effect of the polishing is shown by an optical microscopic image of the surface of the carbon fiber reinforced carbon composite substrate in FIGS. 7 (a) and 7 (b). In the case of (a) before polishing, the height difference of the unevenness is ± 100 μm, whereas in the case after (b) polishing, the height difference is reduced to ± 10 nm. Thereby, for example, the film thickness of a graphene / graphite film produced by a liquid phase growth method or a composite film of nanocarbon and graphene / graphite can be accurately measured.

  As a second procedure, the first carbon fiber reinforced carbon composite material substrate was placed in a glassy carbon reaction vessel, and a flux was disposed on the first carbon fiber reinforced carbon composite material substrate. When the flux was gallium, it was liquid, so it was quantified with a pipette or the like, and when it was SUS304, it was solid, so the sections were weighed and arranged. Next, a second carbon fiber reinforced carbon composite material substrate was placed on the alloy flux.

  As a third procedure, the reaction vessel prepared above was set in an electric furnace and then evacuated to a vacuum. Next, in order to remove volatile impurities in the system, the system was heated from room temperature to 300 ° C. and kept at the same temperature for 60 minutes. Then, after heating for 120 minutes from 300 degreeC to 1500 degreeC, it cooled over 1500 minutes from 1500 degreeC to 700 degreeC. Finally, it cooled by natural heat radiation from 700 degreeC to room temperature.

As a fourth procedure, the flux was removed from the substrate. When the flux was gallium, the gallium once melted at room temperature (about 20 ° C.) was a liquid because it was in a supercooled state. After removing most of the gallium with a pipette or the like, the substrate was immersed in hydrochloric acid at 120 ° C. for 30 minutes in order to completely remove the gallium residue on the substrate. Next, the substrate was washed in the order of water, acetone, and isopropyl alcohol, and dried by blowing nitrogen. Finally, the substrate was heated at 200 ° C. for 30 minutes to remove water, solvent, and the like.
When the flux was SUS304, the flux adhered to the substrate and could not be peeled off, so the substrate was immersed in 120 ° C. hydrochloric acid for 120 minutes to dissolve and remove the flux. However, a portion that cannot be completely removed by acid treatment is observed, which is probably due to the fixation of carbides (such as Fe ₃ C). Next, the substrate was washed in the order of water, acetone, and isopropyl alcohol, and dried by blowing nitrogen. Finally, the substrate was heated at 200 ° C. for 30 minutes to remove water, solvent, and the like.

  Next, the result of this comparative example will be described.

  FIGS. 7C and 7D are optical microscope images of the surface of the carbon fiber reinforced carbon composite material obtained as a result of applying the liquid phase growth method using only gallium and only SUS304 as a flux, respectively.

  When the flux of (c) is only gallium, the graphene / graphite film grows sparsely rather than a single plate, and the two-dimensional size of each graphene / graphite crystal is also as small as 1 μm or less. The average film thickness of the graphene / graphite film is 25 nm, which is far from 100 nm.

Further, when the flux (d) is only SUS304, the substrate is very rough as a result of the flux being fixed to the substrate. This observation result means that the peelability cannot be ensured only with the transition metal. Furthermore, the important point is that no graphene / graphite film growth is observed. This observation result can be interpreted as that, in the case of a transition metal-only flux, dissolved carbon does not precipitate as graphene / graphite, but precipitates as a carbide (such as Fe ₃ C) combined with the transition metal. The reason for the latter is considered to be due to the fact that the transition metal alone is too high in carbon solubility.

  Finally, the conclusion of this comparative example will be described.

From the above results, it is proved that even if liquid phase growth is attempted using only gallium as a flux, a graphene / graphite film with a film thickness of 100 nm or more cannot be expected. Further, it is proved that a graphene / graphite film cannot be formed even if liquid phase growth is attempted using only a transition metal having a significantly higher carbon solubility than gallium as a flux.
Example 1
In this example, the condition C ₃ described above, that is, for the purpose of determining the lower limit of the transition metal ratio in the alloy flux in which the graphene / graphite film thickness is 100 nm or more and the effect of transition metal addition becomes significant, The results of coating a carbon fiber reinforced carbon composite with a graphene / graphite film by liquid phase growth using an alloy flux are described. Here, a case where a gallium-nickel alloy is used as an alloy flux will be described.

  Manufacture followed the process of the manufacturing method shown in FIG. The specific procedure is as follows.

  As a first procedure, two surface-polished carbon fiber reinforced carbon composite material substrates were prepared as carbon sources / coating objects.

  As a second procedure, the first carbon fiber reinforced carbon composite material substrate is placed in a glassy carbon reaction vessel, and liquid gallium and solid as an alloy flux are placed on the first carbon fiber reinforced carbon composite material substrate. Of nickel was placed. The nickel ratio in the alloy flux is 1 wt% (Ga: Ni = 99: 1), 3 wt% (Ga: Ni = 97: 3), 10 wt% (Ga: Ni = 90: 10), respectively. We prepared what was adjusted to be. For comparison, a 100% gallium flux not containing nickel was also prepared. Next, a second carbon fiber reinforced carbon composite material substrate was placed on the alloy flux.

As a third procedure, the reaction vessel prepared above was set in an electric furnace and then evacuated to a vacuum.
Then, for the purpose of removing volatile impurities in the system, after further heating from 1 to 120 ° C. for 120 minutes and maintaining the same temperature for 60 minutes for the purpose of further melting gallium and nickel to form a uniform alloy. And cooled to 700 ° C. for 60 minutes. Then, after heating for 60 minutes from 700 degreeC to 1300 degreeC, it cooled over 1 hour from 1300 degreeC to 700 degreeC. This 1300 ° C. heating and 700 ° C. cooling was repeated 10 times in total. This operation is to suppress the generation of polynuclear and promote the growth of the graphene / graphite film over a wide area in a two-dimensional plane. Finally, it cooled to room temperature by natural heat dissipation.
In addition, when the flux weight was compared before and after liquid phase growth, it was confirmed that the transpiration of gallium in the flux was suppressed by adding nickel to the flux.

As a fourth procedure, the alloy flux was removed from the substrate. At room temperature, the alloy flux is almost liquid with a nickel ratio of 1% by weight or less, and in the range from 3% to 10% by weight, a solid metal compound (Ga ₄ Ni) is dispersed in liquid gallium. It was. Therefore, according to the process of FIG. 6, the substrate was immersed in hydrochloric acid at 120 ° C. for 30 minutes in order to completely remove the gallium residue. Next, the substrate was washed in the order of water, acetone, and isopropyl alcohol, and dried by blowing nitrogen. Further, if necessary, the substrate was heated at 200 ° C. for 30 minutes to remove water, solvent, and the like.

  Next, the results of this example will be described.

  Referring to FIG. 8, (a) is gallium only, (b), (c), and (d) are graphene / graphite film coated carbon fiber reinforced carbon produced by a liquid phase growth method using a gallium-nickel alloy flux. It is an optical microscope image of a composite material.

  When the flux of (a) is only gallium, the graphene / graphite crystal size is about 10 μm, which is larger than that of the comparative example (see FIG. 7C) due to repeated heating and cooling effects. The growth of the film is sparse and dense, and the average film thickness does not reach 50 nm and 100 nm.

  On the other hand, when the flux of (b) is a gallium-nickel alloy with a nickel ratio of 1% by weight, the density of graphene / graphite crystals increases and the film thickness reaches an average value of 100 nm. Further, when the nickel ratio in the alloy flux is increased, as shown in (c) and (d) in the case of using a gallium-nickel alloy flux whose nickel ratio is 3 wt% and 10 wt%, respectively, graphene graphite The density of the crystals further increases, and finally, when the nickel ratio in the alloy flux is 10% by weight, the graphene / graphite film covers the entire surface of the substrate. The average film thicknesses of the graphene / graphite films are 300 nm and 1 μm in (c) and (d), respectively. The film thickness of the graphene / graphite film is an increasing function of the nickel ratio in the alloy flux. In addition, no precipitation of carbide is observed on the surfaces of (b), (c), and (d).

  Finally, the conclusion of this example will be described.

As described above, as shown in this example, it is confirmed that the addition of nickel to the flux has a remarkable effect on the thickening of the graphene / graphite film in addition to the suppression of gallium transpiration. When the nickel ratio in the alloy flux is 1% by weight, the thickness of the graphene / graphite film reaches 100 nm. This tendency is the same when the transition metal added to the alloy flux is iron, cobalt, or the like. Therefore, the lower limit of the condition C ₃ , that is, the transition metal ratio in the alloy in which the effect of the transition metal addition becomes remarkable when the film thickness of the graphite film is 100 nm or more is determined to be 1% by weight.
(Example 2)
In this example, the above-described condition C ₁ , that is, the upper limit of the transition metal ratio in which carbon dissolved in the alloy flux of the typical element metal and the transition metal during heating does not precipitate as a carbide combined with the transition metal during cooling, and In order to determine the upper limit of the transition metal ratio in the alloy flux in which the releasability due to the addition of the typical element metal is ensured under the condition C ₂ , the carbon fiber reinforced carbon composite material is obtained by a liquid phase growth method using the alloy flux. The results of coating with a graphene / graphite film will be described. Here, a case where gallium / iron alloy is used as a flux will be described.

  Manufacture followed the process of the manufacturing method shown in FIG. The specific procedure is as follows.

  As a first procedure, two surface-polished carbon fiber reinforced carbon composite material substrates were prepared as carbon sources / covering objects.

  As a second procedure, the first carbon fiber reinforced carbon composite material substrate is placed in a glassy carbon reaction vessel, and liquid gallium and solid as an alloy flux are placed on the first carbon fiber reinforced carbon composite material substrate. Arranged iron. The iron ratio in the alloy flux is 20% by weight (Ga: Fe = 80: 20), 30% by weight (Ga: Fe = 70: 30), and 40% by weight (Ga: Fe = 60: 40), respectively. 50% by weight (Ga: Fe = 50: 50). Next, a second carbon fiber reinforced carbon composite material substrate was placed on the alloy flux.

  As a third procedure, the reaction vessel prepared above was set in an electric furnace and then evacuated to a vacuum. Next, in order to remove volatile impurities in the system, the system was heated from room temperature to 300 ° C. and kept at the same temperature for 60 minutes. Furthermore, for the purpose of melting gallium and iron into a uniform alloy, heating was carried out to 1300 ° C. over 120 minutes and maintained at the same temperature for 60 minutes, and then cooled to 700 ° C. over 60 minutes. Then, after heating for 60 minutes from 700 degreeC to 1300 degreeC, it cooled over 1 hour from 1300 degreeC to 700 degreeC. This 1300 ° C. heating and 700 ° C. cooling was repeated 10 times in total, and then cooled to room temperature by natural heat dissipation.

  As a fourth procedure, the alloy flux was removed from the substrate. At room temperature, the alloy flux was solid with a transition metal ratio of 20% by weight or more, and in this example, any gallium / iron alloy flux did not adhere to the substrate and could be peeled naturally. In addition, the residue of the alloy flux was not confirmed on the board | substrate by observation with an optical microscope.

  Next, the results of this example will be described.

  FIG. 9 is an optical microscope image of a graphene / graphite film-coated carbon fiber reinforced carbon composite produced by a liquid phase growth method using a gallium / iron alloy flux. 9 (a), (b), (c), and (d), the iron ratio in the alloy flux is 20 wt% (Ga: Fe = 80: 20) and 30 wt% (Ga: Fe = 70, respectively). : 30), 40% by weight (Ga: Fe = 60: 40), and 50% by weight (Ga: Fe = 50: 50).

  When the iron ratio in the alloy flux of (a) is 20% by weight, the entire surface of the substrate is completely covered with a single sheet of graphene / graphite film. The two-dimensional spread of the graphene / graphite film extends to several tens of μm square, and the average film thickness is 2 μm. The voids originally present on the surface of the substrate are filled with the graphene / graphite film, and the graphene / graphite film is closely adhered to and integrated with the substrate.

On the other hand, when the iron ratio in the alloy flux of (b) is 30% by weight, the surface is smooth and roughening is not observed, but no graphene / graphite film is formed. Further, there is no trace of carbide (Fe ₃ C) on the surface. This observation result means that in the case of a flux with an iron ratio of 30% by weight, its carbon solubility is too great for graphene / graphite formation. The reason for this is thought to be that graphitization and carbide formation compete in the alloy flux, and when the dissolved carbon concentration is high, the formation of carbide has priority over the formation of graphene and graphite. The reason why the carbide is not seen on the surface is considered to be that the carbide stays inside the alloy flux.

When the iron ratio in (c) is 40% by weight, no graphene / graphite film growth is observed even in the case of 50% by weight in (d). Moreover, the inside of the carbon fiber existing on the substrate surface is eroded as if it was removed. This observation result agrees with the above interpretation, and it is considered that carbon on the substrate surface is not discharged while being taken in as carbide in the alloy flux. From the above results, the upper limit value _{C 1} may be determined as 20 wt%.

In addition, it is known from a separate experiment that as the iron ratio in the alloy flux becomes larger than 50% by weight, separation of the alloy flux and the substrate becomes gradually difficult and the peelability is lost. From this result, the upper limit value _{C 2} may be determined as 50 wt%.

  Finally, the conclusion of this example will be described.

In the case of a gallium / iron alloy flux, the ratio of transition metal in which the carbon dissolved in the alloy flux of the typical element metal and transition metal upon heating does not precipitate as a carbide combined with the transition metal upon cooling is 20% by weight or less. It is concluded that the transition metal ratio in the alloy flux that ensures the peelability due to the addition of metal is 50% by weight or less.
(Example 3)
In this example, the above-described condition C ₁ , that is, the upper limit of the transition metal ratio in which carbon dissolved in the alloy flux of the typical element metal and the transition metal during heating does not precipitate as a carbide combined with the transition metal during cooling, and In order to determine the upper limit of the transition metal ratio in the alloy flux in which the releasability due to the addition of the typical element metal is ensured under the condition C ₂ , the carbon fiber reinforced carbon composite material is obtained by a liquid phase growth method using the alloy flux. The results of coating with a graphene / graphite film will be described. Here, a case where a gallium-cobalt alloy is used as a flux will be described.

  Manufacture followed the process of the manufacturing method shown in FIG. The specific procedure is the same as in the second embodiment.

  Next, the results of this example will be described.

  FIG. 10 is an optical microscope image of a graphene / graphite film-coated carbon fiber reinforced carbon composite material produced by a liquid phase growth method using a gallium / cobalt alloy flux. 10 (a), (b), (c), and (d), the cobalt ratio in the alloy flux is 20 wt% (Ga: Co = 80: 20) and 30 wt% (Ga: Co = 70, respectively). : 30), 40% by weight (Ga: Co = 60: 40), and 50% by weight (Ga: Co = 50: 50).

  When the cobalt ratios in the alloy fluxes (a) and (b) are 20% by weight and 30% by weight, respectively, the entire substrate surface is completely covered with a single sheet of graphene / graphite film. ing. The two-dimensional spread of the two graphene / graphite films extends to several tens of μm square, and the average film thicknesses are 2 μm and 3 μm, respectively. The voids originally present on the surface of the substrate are filled with the graphene / graphite film, and both the graphene / graphite films are closely adhered to and integrated with the substrate.

On the other hand, when the cobalt ratio in the alloy flux of (c) is 40% by weight, the surface is smooth and roughening is not observed, but no graphene / graphite film is formed. Also, there is no trace of cobalt carbide on the surface.
This observation result means that in the case of an alloy flux having a cobalt ratio of 40% by weight, its carbon solubility is too great for graphene / graphite formation. The reason for this is thought to be that graphitization and carbide formation compete in the alloy flux, and when the dissolved carbon concentration is high, the formation of carbide has priority over the formation of graphene and graphite. The reason why the carbide is not seen on the surface is considered to be that the carbide is precipitated inside the alloy flux.

Even when the cobalt ratio in the alloy flux of (d) is 50% by weight, no growth of the graphene / graphite film is observed. Moreover, the inside of the carbon fiber existing on the substrate surface is eroded as if it was removed. This observation result agrees with the above interpretation, and it is considered that carbon on the substrate surface is not discharged while being taken in as carbide in the alloy flux. From the above results, the upper limit value _{C 1} may be determined as 30 wt%.

As in the case of the iron-added alloy flux, as the cobalt ratio in the alloy flux exceeds 50% by weight, the separation of the alloy flux and the substrate becomes gradually difficult, and the peelability is lost. From this result, the upper limit value _{C 2} may be determined as 50 wt%.

  Finally, the conclusion of this example will be described.

In the case of gallium-cobalt alloy flux, the percentage of transition metal in which carbon dissolved in the alloy flux of typical element metal and transition metal during heating does not precipitate as carbide combined with transition metal during cooling is 30% by weight or less, typical element It is concluded that the transition metal ratio in the alloy flux that ensures the peelability due to the addition of metal is 50% by weight or less.
Example 4
In this example, the above-described condition C ₁ , that is, the upper limit of the transition metal ratio in which carbon dissolved in the alloy flux of the typical element metal and the transition metal during heating does not precipitate as a carbide combined with the transition metal during cooling, and In order to determine the upper limit of the transition metal ratio in the alloy flux in which the releasability due to the addition of the typical element metal is ensured under the condition C ₂ , the carbon fiber reinforced carbon composite material is obtained by a liquid phase growth method using the alloy flux. The results of coating with a graphene / graphite film will be described. Here, a case where a gallium-nickel alloy is used as a flux will be described.
Manufacture followed the process of the manufacturing method shown in FIG. The specific procedure is the same as in Examples 1, 2, and 3.

  Next, the results of this example will be described.

FIG. 11 is an optical microscope image of a graphene / graphite film-coated carbon fiber reinforced carbon composite produced by a liquid phase growth method using a gallium / nickel alloy flux.
11 (a), (b), (c), and (d), the nickel ratio in the alloy flux is 20 wt% (Ga: Ni = 80: 20) and 30 wt% (Ga: Ni = 70, respectively). : 30), 40% by weight (Ga: Ni = 60: 40), and 50% by weight (Ga: Ni = 50: 50).

  When the nickel ratio in the alloy flux of (a), (b), and (c) is 20% by weight, 30% by weight, and 40% by weight, respectively, all three are made of a single sheet of graphene / graphite film The entire substrate surface is completely covered. The three-dimensional spread of the three graphene / graphite films extends to several tens of μm square, and the average film thicknesses are 2 μm, 3 μm, and 4 μm, respectively. The voids originally present on the surface of the substrate are filled with the graphene / graphite film, and the graphene / graphite film is in close contact with and integrated with the substrate.

On the other hand, when the cobalt ratio in the alloy flux of (d) is 50% by weight, the surface is smooth and roughening is not observed, but no graphene / graphite film is formed. Also, there are no traces of carbides on the surface.
This observation means that in the case of an alloy flux having a nickel ratio of 50% by weight, its carbon solubility is too great for graphene / graphite formation. The reason for this is thought to be that graphitization and carbide formation compete in the alloy flux, and when the dissolved carbon concentration is high, the formation of carbide has priority over the formation of graphene and graphite. The reason why the carbide is not observed on the surface is considered to be that metastable carbide precipitates inside the alloy flux. From the above results, the upper limit value _{C 1} may be determined as 40 wt%.

As in the case of the iron-added or cobalt-added alloy flux, as the nickel ratio in the alloy flux becomes larger than 50% by weight, it becomes difficult to separate the alloy flux from the substrate and the peelability is lost. . From this result, the upper limit value _{C 2} may be determined as 50 wt%.

  Finally, the conclusion of this example will be described.

  In the case of a gallium-nickel alloy flux, the ratio of transition metal in which carbon dissolved in the alloy flux of typical element metal and transition metal upon heating does not precipitate as carbide combined with transition metal upon cooling is 40% by weight or less, typical element It is concluded that the transition metal ratio in the alloy flux that ensures the peelability due to the addition of metal is 50% by weight or less.

Note that in other transition metals, not found what condition C ₁ is more than 40 wt%, and the condition C ₂ were 50 wt% or less.

Therefore, it is generally concluded that the upper limit of the transition metal ratio in the typical element metal / transition metal alloy flux under the condition C is 40% by weight.
(Example 5)
In this example, it is proved that a carbon material can be covered with a composite film of various nanocarbons and graphene / graphite having a film thickness of 100 nm or more.

  Manufacture followed the process of the manufacturing method shown in FIG. The specific procedure is as follows.

As a first procedure, an aqueous suspension of carbon nanohorn, single-walled carbon nanotube, graphene oxide, and nanodiamond was prepared as a nanocarbon source of a composite film of nanocarbon and graphene / graphite.
The concentration of each suspension is 0.1 mg / ml, 1 mg / ml, 1 mg / ml, 5 mg / ml. Each suspension was applied onto a surface-ground carbon fiber reinforced carbon composite substrate using a spin coating method or a dropping method. The average film thickness of the coating film is 100 nm for carbon nanohorns, 200 nm for single-walled carbon nanotubes, 400 nm for graphene oxide, and 1 μm for nanodiamonds, respectively.

  Second, the nanocarbon coated substrate was placed in a glassy carbon reaction vessel, and liquid gallium and solid nickel were placed on the nanocarbon coated substrate as alloy flux. The nickel ratio in the alloy flux is 10% by weight (Ga: Ni = 90: 10). Next, the above-described carbon fiber reinforced carbon composite material was disposed as a carbon source on the alloy flux.

  As a third procedure, the reaction vessel prepared above was set in an electric furnace and then evacuated to a vacuum. Next, in order to remove volatile impurities in the system, the system was heated from room temperature to 300 ° C. and kept at the same temperature for 60 minutes. Furthermore, for the purpose of melting gallium and nickel into a uniform alloy, heating was carried out to 1300 ° C. over 120 minutes and maintained at the same temperature for 60 minutes, and then cooled to 700 ° C. over 60 minutes. Then, after heating for 60 minutes from 700 degreeC to 1300 degreeC, it cooled over 1 hour from 1300 degreeC to 700 degreeC. Finally, it cooled by natural heat radiation from 700 degreeC to room temperature.

As a fourth procedure, the alloy flux was removed from the substrate. At room temperature, the alloy flux was in a state where a solid metal compound (Ga ₄ Ni) was dispersed in liquid gallium. Therefore, according to the process of FIG. 6, the substrate was immersed in hydrochloric acid at 120 ° C. for 30 minutes in order to completely remove the gallium residue. Next, the substrate was washed in the order of water, acetone, and isopropyl alcohol, and dried by blowing nitrogen. Further, if necessary, the substrate was heated at 200 ° C. for 30 minutes to remove water, solvent, and the like.

  Next, the results of this example will be described.

  Referring to FIG. 12, it is an optical microscope image of a carbon fiber reinforced carbon composite material with a composite coating of nanocarbon and graphene / graphite film produced by a liquid phase growth method using a gallium-nickel alloy flux. The types of nanocarbon are (a) carbon nanohorn, (b) single-walled carbon nanotube, (c) graphene oxide, and (d) nanodiamond. Each nanocarbon is fused and integrated through covalent bonds between graphene and graphite formed by liquid phase growth and carbon-carbon. The average film thickness is 300 nm, 400 nm, 600 nm, and 1.2 μm, respectively, and the film thickness is increased by about 200 nm from before the liquid phase growth. This increase in film thickness can be explained by the fact that the graphene / graphite in the composite film grew mainly from carbon derived from a carbon fiber reinforced carbon composite material disposed on the alloy flux as a carbon source. Furthermore, it is also integrated with the carbon fiber reinforced carbon composite material obtained by forming the composite film nanocarbon. It has been found from separate measurements that these composite films have excellent mechanical properties, chemical properties, electronic properties, and thermal properties.

  Finally, the conclusion of this example will be described.

As described above, the results of this example prove that it is possible to coat a carbon material with a composite film of various nanocarbons and graphene / graphite having a film thickness of 100 nm or more.
(Example 6)
In this example, it is proved that various heat resistant materials can be coated with a composite film of single-walled carbon nanotubes and graphene / graphite having a thickness of 100 nm or more.

  Manufacture followed the process of the manufacturing method shown in FIG. The specific procedure is as follows.

As a first procedure, an aqueous suspension of single-walled carbon nanotubes was prepared as a nanocarbon source of a composite film of nanocarbon and graphene / graphite. Each suspension concentration is 1 mg / ml. Using a spin coater, single crystal sapphire: Al ₂ O ₃ (0001) substrate, single crystal sapphire: Al ₂ O ₃ (1-100) substrate, single crystal quartz: SiO ₂ (0001), single crystal silicon carbide: 6H -The said suspension was apply | coated on the SiC (0001) board | substrate. The average film thickness of the coating film is 100 nm, 100 nm, 200 nm, and 200 nm, respectively.

  As a second procedure, each single-walled carbon nanotube-coated substrate was placed in a glassy carbon reaction vessel, and liquid gallium and solid nickel were placed as alloy fluxes on the single-walled carbon nanotube-coated substrate, respectively. The nickel ratio in the alloy flux is 10% by weight (Ga: Ni = 90: 10). Next, a carbon fiber reinforced carbon composite material substrate was disposed as an auxiliary carbon source on the alloy flux.

  As a third procedure, the reaction vessel prepared above was set in an electric furnace and then evacuated to a vacuum. Next, in order to remove volatile impurities in the system, the system was heated from room temperature to 300 ° C. and kept at the same temperature for 60 minutes. Further, for the purpose of melting gallium and nickel to form a uniform alloy, heating was performed up to 1000 ° C. over 120 minutes and maintained at the same temperature for 60 minutes, and then cooling down to 700 ° C. over 60 minutes. Thereafter, heating was performed from 700 ° C. to 1000 ° C. over 60 minutes, and then cooling was performed from 1000 ° C. to 700 ° C. over 60 minutes. Then, it cooled by natural heat radiation from 700 degreeC to room temperature.

As a fourth procedure, the alloy flux was removed from the substrate. At room temperature, the alloy flux was in a state where a solid metal compound (Ga ₄ Ni) was dispersed in liquid gallium. Therefore, according to the process of FIG. 6, the substrate was immersed in hydrochloric acid at 120 ° C. for 30 minutes in order to completely remove the gallium residue. Next, the substrate was washed in the order of water, acetone, and isopropyl alcohol, and dried by blowing nitrogen. Further, if necessary, the substrate was heated at 200 ° C. for 30 minutes to remove water, solvent, and the like.

  Next, the results of this example will be described.

Referring to FIG. 13, there are optical microscope images of various heat-resistant material substrates coated with single-walled carbon nanotubes and a graphene / graphite film composite film produced by a liquid phase growth method using a gallium / nickel alloy flux. The types of heat-resistant materials are (a): Al ₂ O ₃ (0001), (b): Al ₂ O ₃ (1-100), (c) SiO ₂ (0001), (d) 6H—SiC (0001). It is. On each heat-resistant substrate material, single-walled carbon nanotubes are fused and integrated via a graphene / graphite formed by liquid phase growth and a carbon-carbon covalent bond. The average film thicknesses are 150 nm, 150 nm, 250 nm, and 250 nm, respectively, and the film thicknesses increase by about 50 nm from before the liquid phase growth. This increase in film thickness can be explained by the fact that the graphene / graphite in the composite film grew mainly from carbon derived from a carbon fiber reinforced carbon composite material disposed on the alloy flux as a carbon source. Further, these composite films are in close contact with the underlying heat-resistant material substrate. It has been found from separate measurements that these composite films have excellent mechanical properties, chemical properties, electronic properties, and thermal properties.

  Finally, the conclusion of this example will be described.

  As described above, the results of this example prove that various heat-resistant materials can be coated with a composite film of single-walled carbon nanotubes and graphene / graphite having a thickness of 100 nm or more.

A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
(A) contacting an alloy containing a typical element metal and a transition metal with a carbon source, and heating the alloy to dissolve carbon on the surface of the carbon source in the alloy;
(B) By cooling the alloy, a graphene / graphite film or a composite film of nanocarbon and graphene / graphite is deposited on the surface of an object in contact with the alloy.
A method of forming a graphene / graphite film or a composite film of nanocarbon and graphene / graphite,
(Appendix 2)
The formation method according to appendix 1, wherein a film thickness of the graphene / graphite film or the composite film of nanocarbon and graphene / graphite is 100 nm or more.
(Appendix 3)
The typical element metal is at least one selected from the group consisting of gallium (Ga), indium (In), tin (Sn), aluminum (Al), thallium (Tl), lead (Pb), and bismuth (Bi). The forming method according to Supplementary Note 1 or 2.
(Appendix 4)
The transition element metals are scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu). , Zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd) , Lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), mercury (Hg) 4. The forming method according to any one of appendices 1 to 3, having at least one selected from the group consisting of:
(Appendix 5)
The formation method according to any one of supplementary notes 1 to 4, wherein a weight ratio of the transition metal in the alloy is 1 wt% or more and 40 wt% or less.
(Appendix 6)
The carbon source has at least one selected from the group consisting of carbon materials, nanocarbon materials, low molecular organic compounds, artificial high molecular organic compounds, natural high molecular organic compounds, and inorganic compounds containing carbon,
The carbon material includes at least one of amorphous carbon, glassy carbon, crystalline graphite, diamond, carbon fiber, carbon fiber reinforced carbon composite material,
The nanocarbon material includes at least one of carbyne, single-walled nanotube, multi-walled carbon nanotube, fullerene, nanodiamond, graphene, carbon nanohorn, and graphene oxide,
The low molecular organic compound includes at least one of metallocene, naphthalene, anthracene, and pentacene,
The artificial high molecular organic compound includes at least one of Teflon, PMMA (polymethyl methacrylate), and polyethylene,
The natural polymer organic compound includes at least one of protein, nucleic acid, lipid, and polysaccharide,
The inorganic compound containing carbon includes silicon carbide (SiC), boron carbide (B ₄ C), aluminum carbide (Al ₄ C ₃ ), titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), carbonization. Vanadium (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), tungsten carbide (WC), carbon nitride (C ₃ N ₄ ), carbon boron nitride (BCN) The formation method according to any one of appendices 1 to 5, including at least one of the above.
(Appendix 7)
The heat-resistant material has at least one selected from the group consisting of a carbon material, a nanocarbon material, a nitride, a carbide, a fluoride, mica (mica), and diamond,
The carbon material includes at least one of amorphous carbon, glassy carbon, crystalline graphite, diamond, carbon fiber, carbon fiber reinforced carbon composite material,
The nanocarbon material includes at least one of carbyne, single-walled nanotube, multi-walled carbon nanotube, fullerene, nanodiamond, graphene, carbon nanohorn, and graphene oxide,
The oxide includes quartz (SiO ₂ ), alumina, sapphire (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), zinc oxide (ZnO), magnesium oxide (MgO), nickel oxide (NiO), and zirconia (ZrO ₂ ). ), Lithium niobate (LiNbO ₃ ), at least one of lithium tantalate (LiTaO ₃ ),
The nitride includes at least one of boron nitride (BN), aluminum nitride (AlN), gallium nitride (GaN), carbon nitride (C ₃ N ₄ ), and carbon boron nitride (BCN),
The carbide is silicon carbide (SiC), boron carbide (B ₄ C), aluminum carbide (Al ₄ C ₃ ), titanium carbide (TiC), or zirconium carbide (ZrC). Including at least one of hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), tungsten carbide (WC),
The formation method according to any one of appendices 1 to 6, wherein the fluoride includes at least one of barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ), and magnesium fluoride (MgF ₂ ). .
(Appendix 8)
8. The forming method according to any one of appendices 1 to 7, wherein a nanocarbon material is previously formed on the object.
(Appendix 9)
The nanocarbon material formed on the object has at least one selected from the group consisting of carbyne, single-walled nanotubes, multi-walled carbon nanotubes, fullerenes, nanodiamonds, graphene, carbon nanohorns, and graphene oxide. Item 9. The forming method according to any one of Items 1 to 8.
(Appendix 10)
The formation method according to claim 1, wherein the alloy is removed after the graphene / graphite film or the composite film of nanocarbon and graphene / graphite is deposited.
(Appendix 11)
11. The forming method according to any one of appendices 1 to 10, wherein the object has heat resistance.
(Appendix 12)
The forming method according to any one of appendices 1 to 11, wherein the heating temperature of the alloy is 800 ° C. or higher.
(Appendix 13)
The forming method according to any one of appendices 1 to 12, wherein the cooling rate of the alloy is 100 ° C./min or less.
(Appendix 14)
14. The method according to any one of appendices 1 to 13, wherein the heating and cooling of the alloy are repeated.

  Examples of utilization of the present invention include intermediate materials made of carbon materials, such as fishing rods, sports and leisure equipment such as tennis and badminton rackets, members of various industrial equipment and X-ray related medical equipment, civil engineering architecture and aerospace structure Materials, space elevator cables, electronic parts such as electrodes in the electrical industry, heat dissipation materials, heat pipes and the like.

Further, the present invention can be used in industrial fields such as chemistry and materials for the purpose of surface strengthening of various heat-resistant inorganic materials.
Furthermore, according to the present invention, it is possible to fuse the exceptional electronic physical properties and optical properties of nanocarbon and graphene, as well as excellent mechanical and chemical properties. It is expected to be used in industrial fields such as spintronics.

DESCRIPTION OF SYMBOLS 1 Carbon source 2 Flux 3 Coating target object 4 Carbon 5 Graphene graphite film 11 Carbon source carrier 12 Carbon source 13 Alloy flux 14 Structure 15 Residue 16 Graphene / graphite film or composite film of nanocarbon and graphene graphite

Claims (10)

(A) contacting an alloy containing a typical element metal and a transition metal with a carbon source, and heating the alloy to dissolve carbon on the surface of the carbon source in the alloy;
(B) By cooling the alloy, a graphene / graphite film or a composite film of nanocarbon and graphene / graphite is deposited on the surface of an object in contact with the alloy.
A method of forming a graphene / graphite film or a composite film of nanocarbon and graphene / graphite,   The formation method according to claim 1, wherein a film thickness of the graphene / graphite film or a composite film of nanocarbon and graphene / graphite is 100 nm or more.   The typical element metal is at least one selected from the group consisting of gallium (Ga), indium (In), tin (Sn), aluminum (Al), thallium (Tl), lead (Pb), and bismuth (Bi). The forming method according to claim 1 or 2.   The transition element metals are scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu). , Zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd) , Lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), mercury (Hg) The formation method according to claim 1, which has at least one selected from the group consisting of:   The formation method according to claim 1, wherein a weight ratio of the transition metal in the alloy is 1% by weight or more and 40% by weight or less. The carbon source has at least one selected from the group consisting of carbon materials, nanocarbon materials, low molecular organic compounds, artificial high molecular organic compounds, natural high molecular organic compounds, and inorganic compounds containing carbon,
The carbon material includes at least one of amorphous carbon, glassy carbon, crystalline graphite, diamond, carbon fiber, carbon fiber reinforced carbon composite material,
The nanocarbon material includes at least one of carbyne, single-walled nanotube, multi-walled carbon nanotube, fullerene, nanodiamond, graphene, carbon nanohorn, and graphene oxide,
The low molecular organic compound includes at least one of metallocene, naphthalene, anthracene, and pentacene,
The artificial high molecular organic compound includes at least one of Teflon, PMMA (polymethyl methacrylate), and polyethylene,
The natural polymer organic compound includes at least one of protein, nucleic acid, lipid, and polysaccharide,
The inorganic compound containing carbon includes silicon carbide (SiC), boron carbide (B ₄ C), aluminum carbide (Al ₄ C ₃ ), titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), carbonization. Vanadium (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), tungsten carbide (WC), carbon nitride (C ₃ N ₄ ), carbon boron nitride (BCN) The formation method of any one of Claim 1 to 5 containing at least 1 type in these. The heat-resistant material has at least one selected from the group consisting of a carbon material, a nanocarbon material, a nitride, a carbide, a fluoride, mica (mica), and diamond,
The carbon material includes at least one of amorphous carbon, glassy carbon, crystalline graphite, diamond, carbon fiber, carbon fiber reinforced carbon composite material,
The nanocarbon material includes at least one of carbyne, single-walled nanotube, multi-walled carbon nanotube, fullerene, nanodiamond, graphene, carbon nanohorn, and graphene oxide,
The oxide includes quartz (SiO ₂ ), alumina, sapphire (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), zinc oxide (ZnO), magnesium oxide (MgO), nickel oxide (NiO), and zirconia (ZrO ₂ ). ), Lithium niobate (LiNbO ₃ ), at least one of lithium tantalate (LiTaO ₃ ),
The nitride includes at least one of boron nitride (BN), aluminum nitride (AlN), gallium nitride (GaN), carbon nitride (C ₃ N ₄ ), and carbon boron nitride (BCN),
The carbide is silicon carbide (SiC), boron carbide (B ₄ C), aluminum carbide (Al ₄ C ₃ ), titanium carbide (TiC), or zirconium carbide (ZrC). Including at least one of hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (CrC), molybdenum carbide (MoC), tungsten carbide (WC),
The formation according to claim 1, wherein the fluoride includes at least one of barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ), and magnesium fluoride (MgF ₂ ). Method.   The formation method according to claim 1, wherein a nanocarbon material is previously formed on the object.   The nanocarbon material formed on the object has at least one selected from the group consisting of carbyne, single-walled nanotubes, multi-walled carbon nanotubes, fullerenes, nanodiamonds, graphene, carbon nanohorns, and graphene oxide. Item 9. The forming method according to any one of Items 1 to 8.   The formation method according to claim 1, wherein the alloy is removed after the graphene / graphite film or the composite film of nanocarbon and graphene / graphite is deposited.