JP2022160428A - Structure and hydrogen storage structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit an aggregation of a plurality of particles each containing a hydrogen storage metal element.

SOLUTION: In a structure, a plurality of particles each containing hydrogen storage metal element are disposed in a manner alienated with each other in a stationary member. An entirety of a surface of each of the plurality of particles is surrounded by the stationary member. The stationary member contains at least one of an oxide and a nitride. The stationary member includes a base and a film disposed on a surface of the base. The plurality of particles include two or more particles disposed on the surface of the base and each having a different distance from the surface of the base. The film is abutting on an entire surface of the plurality of particles.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to structures and hydrogen storage structures.

A hydrogen storage metal or hydrogen storage alloy can be used as a means of storing hydrogen. Patent Literature 1 describes a method for producing a hydrogen storage alloy. In this manufacturing method, an rf arc plasma is formed in a vacuum vessel with reduced pressure, and vapors of Ti and Cu, or Ti, Cu and Si are reacted in the plasma to produce a Ti—Cu alloy or a Ti—Cu—Si alloy. of fine powder is formed and recovered. According to Patent Document 1, since the fine powder produced by this production method has a large surface area, it realizes a hydrogen storage capacity about 10 to 50 times that of conventional powders.

JP-A-61-270301

Particles containing hydrogen-absorbing metal elements such as hydrogen-absorbing metals and hydrogen-absorbing alloys can generate heat when absorbing hydrogen. In particular, when the size of the particles is reduced in order to increase the surface area of the particles per unit volume, the efficiency of hydrogen storage can be improved, and the amount of heat generated when storing hydrogen can also be increased. A high calorific value can cause the particles to agglomerate. Alternatively, the particles can aggregate when heat is applied to the particles from the outside. Particle agglomeration can reduce the hydrogen storage capacity.

An object of the present invention is to suppress agglomeration of a plurality of particles containing a hydrogen storage metal element.

A first aspect of the present invention relates to a structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other, and the surface of each of the plurality of particles The plurality of the includes two or more particles arranged on the surface of the base and having different distances from the surface of the base, and the film is in contact with the entire surface of each of the plurality of particles.
A second aspect of the present invention relates to a structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other, and the surface of each of the plurality of particles The plurality of the includes two or more particles arranged on the surface of the base and having different distances from the surface of the base, each of the plurality of particles having a distance of 1 nm or more from the surface of the base, and It is in the range of 10 nm or less.
A third aspect of the present invention relates to a structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other, and the surface of each of the plurality of particles The plurality of the contains two or more particles arranged on the surface of the base and having different distances from the surface of the base, and the plurality of particles are separated from each other even after heat treatment at 400 ° C. for 10 hours It is
A fourth aspect of the present invention relates to a structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other, and the surface of each of the plurality of particles The whole is surrounded by the fixing member, and the fixing member is MgO, ZrO ₂ , Y ₂ O. ₃ , CaO, Al ₂ O. ₃ , Si ₃ N. ₄ and AlN, the fixing member includes a base and a film disposed on the surface of the base, and the plurality of particles are disposed on the surface of the base and the base two or more particles having different distances from said surface.
A fifth aspect of the present invention relates to a hydrogen storage structure in which a plurality of particles each containing a hydrogen storage metal element are arranged in a stationary member so as to be separated from each other, and each of the plurality of particles The entire surface is surrounded by the anchoring member, the anchoring member comprising at least one of an oxide and a nitride, the anchoring member comprising a substrate and a film disposed over the surface of the substrate.

According to the present invention, agglomeration of a plurality of particles containing a hydrogen-absorbing metal element is suppressed.

1 is a schematic cross-sectional view of a structure according to a first embodiment of the present invention; FIG. 1 is a schematic cross-sectional view of a structure according to a first embodiment of the present invention; FIG. 4A and 4B are views for explaining a method for manufacturing a structure according to the first embodiment of the present invention; FIG. 4A and 4B are views for explaining a method for manufacturing a structure according to the first embodiment of the present invention; FIG. 4A and 4B are views for explaining a method for manufacturing a structure according to the first embodiment of the present invention; FIG. 4A and 4B are views for explaining a method for manufacturing a structure according to the first embodiment of the present invention; FIG. A TEM image of a cross section of a structure according to an example. FIG. 4B is a TEM image of a cross section of the structure according to the example (enlarged view of FIG. 4A). A cross-sectional TEM image of the structure after heat treatment. A cross-sectional TEM image of the structure after heat treatment (magnified view of FIG. 5A). 4B shows the results of EDX analysis of the structure of FIG. 4A. FIG. FIG. 5B shows the results of EDX analysis of the structure of FIG. 5A. Typical sectional drawing of the structure of 2nd Embodiment of this invention. Typical sectional drawing of the structure of 3rd Embodiment of this invention.

The invention will now be described through its exemplary embodiments with reference to the accompanying drawings.

[First embodiment]
1 and 2 show schematic cross-sectional views of a structure 1 according to a first embodiment of the present invention. Here, FIG. 2 corresponds to an enlarged view of a part of the cross section taken along line AA' of FIG. The structure 1 has a structure in which a plurality of particles 3 are arranged in a fixing member 10 such that they are spaced apart from each other.

The fixing member 10 functions to keep the plurality of particles 3 apart from each other even in a high-temperature environment, and functions to fix the positions of the plurality of particles 3, for example. Each of the plurality of particles 3 contains a hydrogen storage metal element. Fixing member 10 may include, for example, substrate 2 and membrane 4 disposed on substrate 2 . The entire surface of each of the plurality of particles 3 is surrounded by the fixing member 10 .

The particles 3 are particles made of a material containing a hydrogen-absorbing metal element, and may contain, for example, at least one of hydrogen-absorbing metal particles and hydrogen-absorbing alloy particles. The hydrogen storage metal element can be, for example, at least one selected from the group consisting of Pd, Ni, Cu, Ti, Nb, Zr, Mg, Mn, V, Fe, and rare earth elements. Hydrogen storage alloys include, for example, Pd/Ni alloys, Pd/Cu alloys, Mg/Zn alloys, Zr/Ni alloys, Zr/Ni/Mn alloys, Ti/Fe alloys, Ti/Co alloys, La/Ni alloys, Re /Ni alloy, Mm/Ni alloy, Ca/Ni alloy, Ti/V alloy, Ti/Cr alloy, Ti/Cr/V alloy, Mg/Ni alloy, Mg/Cu alloy. can be Each dimension of the plurality of particles 3 can be, for example, 2 nm or more and 1000 nm or less. From the viewpoint of increasing the total surface area of the plurality of particles 3, the size of each of the plurality of particles 3 is preferably 2 nm or more and 100 nm or less, more preferably 2 nm or more and 10 nm or less. The particles 3 are preferably crystals, and may be single crystals or polycrystals.

The membrane 4 may consist of a high melting point material, for example a material with a melting point of 1400° C. or higher. Film 4 may contain a plurality of crystallites, but may also be amorphous. The film ₄ is, for example, oxides (eg at _{least one} of MgO, ZrO2, _ZrO2.Y2O3 , CaO _{, SiO2} and _Al2O3 ) and nitrides ₍ eg _Si3N4 and AlN). at least one of).

The base 2 can be, for example, a Si substrate or a base in which a SiO ₂ film is formed on a Si substrate, but may be made of other materials (eg, metal or insulator). The underlayer 2 is preferably made of a material having a melting point of 1400° C. or higher, for example. The underlayer 2 may be a member such as a film made of the same material as the film 4 or a member such as a film made of a material different from that of the film 4 . The base 2 may be an independent member or a member supported by another member.

If the high-melting-point material film 4 that separates the plurality of particles 3 does not exist, when the particles 3 occlude hydrogen and generate heat, two or more particles 3 located nearby may aggregate due to the heat. This increases the size of individual particles and can reduce the hydrogen storage capacity. The existence of the high-melting-point material film 4 that separates the plurality of particles 3 from each other suppresses aggregation of two or more particles 3 located nearby due to heat generated when the particles 3 occlude hydrogen. The presence of the high-melting-point material film 4 also suppresses the formation of an alloy between the particles 3 and the constituents of the film 4 due to the heat generated when the particles 3 occlude hydrogen. The heat resistance required for the film 4 is such that it does not melt when the structure 1 generates heat. The temperature at which the structure 1 generates heat depends on the material of the particles 3, the density of the particles 3 in the structure 1, the pressure of the hydrogen isotope gas, and the like, and cannot be defined uniformly. Therefore, the material of the film 4 is desirably selected according to the usage environment, and is, for example, a material having a melting point of 1400° C. or higher. The distance between the plurality of particles 3 separated by the fixing member 10 is preferably 1 nm or more and 10 nm or less. This is because if the distance between the plurality of separated particles 3 increases, the content of the hydrogen-absorbing metal or hydrogen-absorbing alloy in the structure 1 decreases, which is not preferable.

The plurality of particles 3 may include particles 3 ′ arranged two-dimensionally along the surface of the substrate 2 so as to contact the surface of the substrate 2 . The particles 3 ′ are spaced apart from each other via a membrane 4 and are covered by the membrane 4 .

As illustrated in FIG. 3A, the manufacturing method of the structure 1 is the first step of forming a plurality of particles 3 each containing a hydrogen-absorbing metal element so as to be separated from each other and arranging the individual particles 3 in an island shape. and a second step of forming a membrane 4 to cover each of the plurality of particles 3, as illustrated in FIG. 3B. Here, by performing the treatment including the first step and the second step a plurality of times, it is laminated as illustrated in FIGS. 3C and 3D, and as a result, as illustrated in FIG. A structure 1 having a plurality of particles 3 with different distances from the surface can be obtained. In one example, a plurality of particles 3 can be formed by a sputtering method in the first step, and a film 4 can be formed by a sputtering method so as to directly cover the surface of each particle 3 in the second step. In other examples, at least one of the first and second steps can be performed by a deposition method other than sputtering (eg, CVD, ALD, vacuum deposition, plasma spray). In particular, the use of physical deposition methods to form such hydrogen storage materials is more advantageous than synthesis of hydrogen storage materials in solution or by melting followed by rapid cooling (melt spinning). , controlling the size of the particles of the hydrogen storage metal or hydrogen storage alloy, increasing the content of particles with a desired size, increasing the crystallinity of the particles, suppressing diffusion to adjacent different materials, etc. It becomes possible.

In one example, a process including a first step of forming a plurality of particles 3 by sputtering and a second step of forming film 4 by sputtering can be repeated multiple times. In addition, after the underlayer 2 is carried into the sputtering apparatus, the processes including the first step and the second step can be repeated in the sputtering apparatus without unloading the underlayer 2 from the sputtering apparatus. For example, after substrate 2 has been placed in one process chamber of a sputtering apparatus, repetition of the process including the first and second steps can be performed without substrate 2 being removed from the process chamber. Alternatively, if the sputtering apparatus has a vacuum system that includes multiple process chambers, the first step and the second step can be performed without the substrate 2 being removed from the vacuum system after the substrate 2 has been loaded into the vacuum system of the sputtering apparatus. Repetition of the process, including the steps, may be performed.

In the above example, in the first step, the pressure in the chamber is maintained within the range of 0.02 Pa to 5 Pa, and 0.05 kW to 5 kW is applied to the target made of the constituent material of the particles 3 containing the hydrogen-absorbing metal element. DC power in the range is applied and the chamber can be supplied with an inert gas as the sputtering gas. The target contains at least one of a hydrogen storage metal and a hydrogen storage alloy. The target may be a pure metal or an alloy. The target includes, for example, at least one of the hydrogen-absorbing metals and hydrogen-absorbing alloys listed as the material for forming the particles 3 at the beginning of the first embodiment. A plurality of particles 3 which are spaced apart from one another can thereby be formed. Further, in the second step, the pressure in the chamber is maintained within the range of 0.02 Pa to 5 Pa, power within the range of 0.1 kW to 2 kW is applied to the target made of the constituent material of the film 4, and the chamber is can be supplied with an inert gas.

[Example]
An example in which Cu particles are formed as the particles 3 and an MgO film is formed as the film 4 will be described. In this example, Cu, which is a metal that tends to aggregate relatively easily and can be a constituent element of a hydrogen-absorbing alloy, was selected as a constituent element of the particles 3 in order to verify the aggregation suppression effect.

A Si substrate (backing) having a SiO ₂ film formed on the surface by thermal oxidation is prepared, and the following first and second steps are alternately repeated 10 times each, and then the Cu film is formed in the following third step. Structure 1 was completed by forming A Cu target and an MgO target were attached to the sputtering apparatus, and the treatment including the first step and the second step was repeated 10 times on the underlayer without removing the underlayer from the chamber.
(First step)
In the first step, the pressure in the chamber was maintained at 0.02 Pa, DC power of 0.1 kW was supplied to the Cu target, and argon gas was used as the sputtering gas.
(Second step)
In the second step, the pressure in the chamber was maintained at 0.05 Pa, high frequency power of 1.1 kW was supplied to the MgO target, and argon gas was used as the sputtering gas.
(Third step)
In the third step, the pressure in the chamber was maintained at 0.02 Pa, DC power of 0.1 kW was supplied to the Cu target, and argon gas was used as the sputtering gas.

FIG. 4A is a cross-sectional TEM image of structure 1 formed according to the above example, and FIG. 4B is an enlarged view of a portion of FIG. 4A. FIG. 5A is a TEM image of a cross section of structure 1′ after heat treatment at 400° C. for 10 hours on structure 1 formed according to the above example, and FIG. 5B is a TEM image of FIG. 2 is an enlarged view of the part; FIG. FIG. 6A is the result of EDX analysis of structure 1 of FIG. 4A, and FIG. 6B is the result of EDX analysis of structure 1' of FIG. 5A. 6A and 6B, the horizontal axis indicates the distance from the surface of the structures 1 and 1', and the vertical axis indicates the X-ray detection intensity. The structure 1' is a sample for estimating the state of the structure 1 after absorbing hydrogen and generating heat.

In FIG. 6A relating to Structure 1, peaks indicating Mg element and O element are present between peaks indicating Cu element, and the position of the peak indicating Mg element and the position of the peak indicating O element coincide. ing. From this, it can be seen that Cu particles and MgO films are alternately present. Also, from FIG. 4B for structure 1, it can be seen that the Cu particles whose size is controlled to about 5 nm are surrounded by the MgO film.

In FIG. 6B regarding the structure 1′ after heating the structure 1, as in FIG. 6A, there are peaks indicating Mg element and O element between peaks indicating Cu element, indicating Mg element. The position of the peak and the position of the peak indicating the O element match. From this, it can be seen that even after heating, the Cu particles and the MgO film are alternately present, and the original arrangement of the Cu particles is maintained. Further, from FIG. 5B regarding the structure 1 ′, it can be seen that even after heating, the Cu particles are surrounded by the MgO film, and the size of the Cu particles is about 5 nm, maintaining the size before heating. Also, from FIGS. 5A and 5B, it can be read that Cu on the outermost surface, which is not surrounded by MgO, agglomerates by heating.

[Second embodiment]
A second embodiment of the present invention will be described below with reference to FIG. Matters not mentioned in the second embodiment can follow the first embodiment. In the structure 1 of the second embodiment, the inert gas 7 exists in the film 4 (fixing member 10). For example, the content of the inert gas 7 in the film 4 is, for example, 0.5 atomic % or more. Membrane 4 may include a plurality of crystallites. The inert gas 7 exists, for example, at grain boundaries of the plurality of microcrystals. By positively introducing an inert gas into the grain boundaries of the film 4, it is possible to prevent moisture in the air from penetrating into the structure 1 through the grain boundaries, oxidizing the particles 3, and reducing the hydrogen storage capacity. can do.

Further, passages (spaces) can be generated by removing the inert gas 7 taken into the grain boundaries. This passage can function as a passage for hydrogen when hydrogen is absorbed in the structure 1 . Therefore, as the inert gas 7 is actively taken into the film 4 and the number of grain boundaries in the film 4 is increased, hydrogen can reach the inside of the structure 1 more easily, and the hydrogen storage capacity can be improved. can.

For these reasons, the inert gas 7 taken into the structure 1 is preferably removed immediately before allowing the structure 1 (particles 3) to occlude hydrogen. Removal of the inert gas 7 can be done, for example, by heating the structure 1 .

The method of manufacturing the structure 1 of the second embodiment includes a first step of forming a plurality of particles 3 each containing a hydrogen-absorbing metal element so as to be separated from each other, and forming a film 4 so as to cover the plurality of particles 3. and a second step of In particular, by adjusting film formation conditions such as pressure and discharge voltage in the second step, it becomes possible to positively incorporate inert gas atoms into the grain boundaries of the film 4 . Here, by performing the treatment including the first step and the second step a plurality of times, as illustrated in FIG. can be obtained. In one example, in a first step the plurality of particles 3 may be formed by a sputtering method and in a second step the film 4 may be formed by a sputtering method. In other examples, at least one of the first and second steps can be performed by a deposition method other than sputtering (eg, CVD, ALD, vacuum deposition, plasma spray).

In one example, a process including a first step of forming a plurality of particles 3 by sputtering and a second step of forming film 4 by sputtering can be repeated multiple times. In addition, after the underlayer 2 is carried into the sputtering apparatus, the processes including the first step and the second step can be repeated in the sputtering apparatus without unloading the underlayer 2 from the sputtering apparatus. For example, after substrate 2 has been placed in one process chamber of a sputtering apparatus, repetition of the process including the first and second steps can be performed without substrate 2 being removed from the process chamber. Alternatively, if the sputtering apparatus has a vacuum system that includes multiple process chambers, the first step and the second step can be performed without the substrate 2 being removed from the vacuum system after the substrate 2 has been loaded into the vacuum system of the sputtering apparatus. Repetition of the process, including the steps, may be performed.

In the above example, in the first step, the pressure in the chamber is maintained within the range of 0.02 Pa to 5 Pa, and 0.05 kW to 5 kW is applied to the target made of the constituent material of the particles 3 containing the hydrogen-absorbing metal element. DC power in the range is applied and the chamber can be supplied with an inert gas as the sputtering gas. A plurality of particles 3 spaced apart from each other can thereby be formed. In the second step, the pressure in the chamber varies depending on the material of the film 4, etc., and cannot be uniformly defined, but it is preferably low within the pressure range in which plasma is generated, for example, in the range of 0.02 Pa to 5 Pa. maintained at internal pressure. This is because the sputtering gas atoms (inert gas atoms) collided with and reflected by the target do not collide with atoms or ions before reaching the target for film formation (backing layer 2), that is, the retained energy is It is easier for the film 4 (fixed member 10) to be driven into the film 4 (fixed member 10) from the surface of the film 4 (fixed member 10) when it reaches the film formation target without losing it as much as possible. This is because it can be increased.

In addition, the voltage generated in the target made of the constituent material of the film 4 (for example, self-bias voltage in the case of high-frequency discharge) is a voltage specific to the target material used when the sputtering conditions and the sputtering spatial structure are the same. , a voltage corresponding to an energy greater than or equal to that required for sputtering. The greater the excess energy with respect to the energy required for sputtering, the greater the incident energy of the sputtering gas atoms (inert gas atoms) reflected by the target to the film formation object, and the more the sputtering gas atoms (inert gas atoms) are deposited on the film 4. active gas atoms) are easily implanted. For example, the supplied power can be adjusted so that a self-bias voltage within the range of -100 V to -500 V is generated in the target made of the material of which the film 4 is made.

[Third embodiment]
A third embodiment of the present invention will be described below with reference to FIG. Matters not mentioned in the third embodiment can follow the first or second embodiment. The structure 1 of the third embodiment has a coating film 8 so as to cover the film 4 (fixing member 10 ), and the coating film 8 contains the inert gas 7 . The content of the inert gas 7 in the coating film 8 is, for example, 0.5 atomic % or more. In this example, the content of inert gas 7 in coating film 8 is greater than the content of inert gas 7 in film 4 (fixing member 10).

The coating film 8 is a film provided for the purpose of positively taking in the inert gas 7 . Therefore, the elements forming the coating film 8 and the conditions for forming the coating film 8 can be set with the highest priority given to taking the inert gas 7 into the film. By actively taking inert gas into the grain boundaries of the coating film 8, moisture in the air penetrates into the structure 1 through the grain boundaries, oxidizes the particles 3, and reduces the hydrogen storage capacity. can be suppressed.

Further, passages (spaces) can be generated by removing the inert gas 7 taken into the grain boundaries. This passage can function as a passage for hydrogen when hydrogen is absorbed in the structure 1 . Therefore, as the coating film 8 is allowed to actively incorporate the inert gas 7 and the number of grain boundaries in the coating film 8 is increased, hydrogen is more likely to reach the inside of the structure 1, thereby increasing the hydrogen storage capacity. can be improved. For these reasons, as in the second embodiment, the inert gas 7 is preferably removed immediately before allowing the structure 1 (particles 3) to occlude hydrogen. Removal of the inert gas 7 can be done, for example, by heating the structure 1 .

Coating film 8 is preferably made of a material containing an element having a large atomic weight. In other words, the target for forming the coating film 8 is preferably a material containing an element with a large atomic weight. This is for the following reasons. In general, ions of the sputtering gas (that is, the inert gas 7) are accelerated on the surface of the target, collide with the target, eject atoms constituting the target, and some of the ions become atoms and still retain a certain amount of energy. Reflect while holding. Therefore, by using a target containing an element having a large atomic weight, it is possible to increase the energy possessed by the reflected sputtering gas atoms, making it easier for them to be implanted into the coating film 8 . In other words, the amount of sputtering gas (inert gas) taken into the structure 1 by providing the structure 1 with the coating film 8 having an atomic weight or molecular weight greater than that of the film 4 (fixing member 10) can be more. An increase in the inert gas content in the structure 1 enables suppression of oxidation of the particles 3 and an increase in the space for hydrogen to pass, as described above, resulting in an improvement in the hydrogen storage capacity. .

For the same reason as the film 4 (fixing member 10), the coating film 8 is made of a material with a high melting point. When the coating film 8 melts and forms an alloy with the particles 3 and the film 4, the hydrogen absorption capacity of the particles 3 decreases. Heat resistance to the extent that it does not melt is required. Since this heat resistance depends on the material of the particles 3, the density of the particles 3 in the structure 1, the pressure of the hydrogen isotope gas, etc., it is desirable to appropriately select the material of the coating film 8 according to the usage environment. The coating film 8 can be made of, for example, a material with a melting point of 1400° C. or higher. The coating film 8 may be made of the same material as the material forming the film 4, or may be made of another material. Coating film 8 may contain a plurality of crystallites, but may be amorphous. The coating film 8 is, for example, an oxide (for example, at least one of MgO, ZrO ₂ , ZrO ₂ .Y ₂ O ₃ , CaO, SiO ₂ and Al ₂ O ₃ ) and a nitride (for example, Si ₃ N ₄ and at least one of AlN).

The method for manufacturing the structure 1 of the third embodiment includes a first step of forming a plurality of particles 3 each containing a hydrogen-absorbing metal element so as to be separated from each other, and forming a film 4 so as to cover the plurality of particles 3. and a second step of Here, by performing the treatment including the first step and the second step a plurality of times and then performing the third step, the distances from the surface of the base 2 are different from each other, as illustrated in FIG. A structure 1 having a plurality of particles 3 can be obtained. In one example, in a first step a plurality of particles 3 are formed by a sputtering method, in a second step a film 4 is formed by a sputtering method, and in a third step a coating film 8 is formed by a sputtering method. sell. In other examples, at least one of the first, second, and third steps can be performed by a deposition method other than sputtering (e.g., CVD, ALD, vacuum deposition, plasma spray). .

In one example, the first step, followed by the second step, followed by the third step may constitute one cycle, and this cycle may be repeated multiple times. In another example, the first step, followed by the second step, followed by the third step, then followed by the second step are one cycle, and the cycle can be repeated multiple times. Further, after the underlayer 2 is carried into the sputtering apparatus, the processes including the first step, the second step and the third step can be repeated in the sputtering apparatus without unloading the underlayer 2 from the sputtering apparatus. Alternatively, if the sputtering apparatus has a vacuum system that includes a plurality of process chambers, after the substrate 2 is loaded into the vacuum system of the sputtering apparatus, the first step, the second step, and the second step are carried out without the substrate 2 being removed from the vacuum system. Repetition of the process including step and third step may be performed.

In the above example, in the first step, the pressure in the chamber is maintained within the range of 0.02 Pa to 5 Pa, and 0.05 kW to 5 kW is applied to the target made of the constituent material of the particles 3 containing the hydrogen-absorbing metal element. DC power in the range is applied and the chamber can be supplied with an inert gas as the sputtering gas. A plurality of particles 3 spaced apart from each other can thereby be formed. Further, in the second step, the pressure in the chamber is maintained within the range of 0.02 Pa to 5 Pa, power within the range of 0.1 kW to 2 kW is applied to the target made of the constituent material of the film 4, and the chamber is can be supplied with an inert gas. Further, it is desirable that the pressure in the chamber in the third step be as low as possible within the pressure range in which plasma is generated. This is because the sputtering gas atoms (inert gas atoms) collided with and reflected by the target do not collide with other atoms or ions before reaching the film formation target, that is, lose their energy as much as possible. This is because, if the atoms reach the target film formation target without being . Inert gas is supplied so that the pressure in the chamber in the third step is maintained within the range of 0.02 Pa to 5 Pa, for example.

Moreover, the voltage generated in the target made of the constituent material of the coating film 8 is a voltage unique to the target material used, and can be a voltage corresponding to energy higher than the energy required for sputtering. This is because the larger the excess energy with respect to the energy required for sputtering, the greater the incident energy of the sputtering gas atoms (inert gas atoms) reflected by the target toward the film formation object, and the coating film 8 This is because sputtering gas atoms (inert gas atoms) are easily taken in. For example, the power supply can be adjusted so that a self-bias voltage within the range of -100 V to -500 V is generated in the target made of the constituent material of the coating film 8 .

Claims (5)

A structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other,
the entire surface of each of the plurality of particles is surrounded by the fixing member;
the fixing member comprises at least one of an oxide and a nitride;
the fixing member includes a substrate and a film disposed on the surface of the substrate;
The plurality of particles includes two or more particles arranged on the surface of the base and having different distances from the surface of the base,
A structure, wherein the film is in contact with the entire surface of each of the plurality of particles. A structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other,
the entire surface of each of the plurality of particles is surrounded by the fixing member;
the fixing member comprises at least one of an oxide and a nitride;
the fixing member includes a substrate and a film disposed on the surface of the substrate;
The plurality of particles includes two or more particles arranged on the surface of the base and having different distances from the surface of the base,
The distance from the surface of the base in each of the plurality of particles is in the range of 1 nm or more and 10 nm or less.
A structure characterized by A structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other,
the entire surface of each of the plurality of particles is surrounded by the fixing member;
the fixing member comprises at least one of an oxide and a nitride;
the fixing member includes a substrate and a film disposed on the surface of the substrate;
The plurality of particles includes two or more particles arranged on the surface of the base and having different distances from the surface of the base,
the plurality of particles are separated from each other even after heat treatment at 400° C. for 10 hours;
A structure characterized by A structure in which a plurality of particles each containing a hydrogen-absorbing metal element are arranged in a fixing member so as to be separated from each other,
the entire surface of each of the plurality of particles is surrounded by the fixing member;
The fixing member is MgO, ZrO ₂ , Y ₂ O. ₃ , CaO, Al ₂ O. ₃ , Si ₃ N. ₄ and at least one of AlN,
the fixing member includes a substrate and a film disposed on the surface of the substrate;
The plurality of particles includes two or more particles arranged on the surface of the base and having different distances from the surface of the base.
A structure characterized by A hydrogen storage structure in which a plurality of particles each containing a hydrogen storage metal element are arranged in a stationary member so as to be spaced apart from each other,
the entire surface of each of the plurality of particles is surrounded by the fixing member;
the fixing member comprises at least one of an oxide and a nitride;
The fixing member includes an underlayer and a film disposed on the surface of the underlayer,
A hydrogen storage structure characterized by:

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