JPH0565512A - Transition metal alloy and method for producing the same - Google Patents

Abstract

(57) [Summary] [Structure] The present invention irradiates a mixture containing two or more kinds of transition metal compounds with light to effect infrared multiphoton decomposition of the compounds.
Methods for producing novel transition metal alloy fine particles or transition metal alloy thin films that have not been obtained as final products as a result of dielectric breakdown, thermal decomposition, ultraviolet photolysis, and transition metal alloys manufactured by those methods Regarding [Effect] By the method of the present invention, it has become possible to produce a novel transition metal alloy which has not existed in the air at room temperature, such as a transition metal alloy having a high temperature stable phase.
Further, the method of the present invention makes it possible to produce transition metal alloy fine particles having a particle size of about 10 nm and a uniform particle size and a thin film of a transition metal alloy having a uniform thickness of about nm. The transition metal alloy obtained by the method of the present invention can be applied to magnetic materials, sensors, memories, composite materials, as well as catalysts, sintering, electronic materials and the like.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the production of an alloy containing two or more kinds of transition metal alloys (hereinafter referred to as transition metal alloys) by light irradiation of a laser or a powerful lamp, and more specifically two or more kinds. The present invention relates to a method for producing fine particles, powder or thin film of a transition metal alloy by photolysis of a raw material gas containing the transition metal compound, and a transition metal alloy produced by the method.

[0002]

2. Description of the Related Art An alloy is usually one obtained by mixing two or more kinds of metals at a temperature equal to or higher than their melting points and then cooling and solidifying them. Conventional fusion and solidification methods can produce alloys of a combination of two transition metals. For example, most combinations of iron alloys such as iron-nickel, iron-titanium, iron-copper, iron-platinum can be produced. In addition to metals, there are also transition metal alloys containing small amounts of non-metals such as carbon and silicon. Generally, alloys have high practical value because they have physical and chemical properties different from the properties of the metal of each component. Also, like metals, alloys undergo phase transitions with changes in temperature. At the same time, the properties of the alloy, such as the tissue state, structure, and magnetic properties, change with changes in temperature. At room temperature, there is a room temperature stable phase of the alloy, and at high temperature there is a high temperature stable phase. With the conventional melting and solidification methods, it was not possible to isolate the high temperature stable phase of the alloy at room temperature.

In the case of an iron-cobalt alloy having a cobalt content of 50% or less, the α phase is a stable phase in the temperature range of 910 to 970 ° C or less. On the other hand, 1400 to above this temperature range
In the temperature range of 1500 ° C. or less, the γ-phase iron-cobalt alloy is stable. Therefore, the iron-cobalt alloy changes from the α phase to the γ phase in the process of increasing the temperature from room temperature to a high temperature of 910 to 970 ° C. or higher, and on the contrary, changes from the γ phase to the α phase in the process of cooling from high temperature to room temperature. . That is, the γ-phase iron-cobalt alloy is 1400 to 150 at 910 to 970 ° C or higher.
It exists only in the temperature range of 0 ° C. or lower and is difficult to isolate at room temperature.

Since the conventional melting and solidifying method consists of a melting process and a cooling solidifying process of a transition metal in a high temperature furnace, it is difficult to control the temperature and alloy composition, the thermal stability of the reaction vessel and the influence of the vessel wall. Is a problem. The transition metal alloy produced by the conventional method can be made into a fine powder by a pulverization method, but the particle size of the fine powder is up to the submicron order (0.1 μm). In general, it has not been possible to produce ultrafine particles having a particle size of about 10 nm by a pulverization method.

By the way, various metal fine particles are produced by a method for producing metal fine particles by laser.
It is also applied to the manufacturing method of iron fine particles, Nd: YAG of iron plate
Generation of fine iron particles by laser irradiation heating evaporation method [Tomio Ariyasu, Shoji Haru, Akira Matsunawa, Seiji Katayama, Laser Research, 1
5 , 38 (1987)], FeA (CO) ₅ TEA CO 2 laser dielectric breakdown of iron fine particles [CWDraper, Metal]
lurgical Transactions A, 11A, 349 (1980)], Production of γ-iron fine particles by the same method [Takahiko Takewaki, Shuji Kato, Kazuo Takeuchi, Yoshihiro Makide, Ken Tominaga, Laser Science Research, 8 , 71
(1986)], TEAC of a mixture of Fe (CO) ₅ and SF 6
Synthesis of γ-iron ultrafine particles via SF6 infrared photosensitization by O2 laser irradiation [Tetsuro Majima, Tatsuki Kawamura, Shigeru Ishikawa, Tadahiro Ishii, Miyahara Tetsushu, Michio Takami, JP-A-3030705] has been reported. . According to this method for producing iron fine particles by laser, γ-iron originally in a high temperature stable phase can be produced at room temperature. However, it is not known that a transition metal alloy can be produced by the above method.

[0006]

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a method for producing a transition metal alloy having a high temperature stable phase which cannot be produced by a conventional method. Further, the present invention provides fine particles of a transition metal alloy having a uniform particle diameter of about 10 nm, a uniform transition metal alloy powder having a uniform particle diameter, and a uniform transition metal alloy thin film having a thickness of about nm. It aims at providing the method of manufacturing.

A further object of the present invention is to provide a method for producing a transition metal alloy that can be easily controlled. Still another object of the present invention is to provide a transition metal alloy obtained by the above method.

[0008]

As a result of diligent efforts, the inventors of the present invention have succeeded in developing an alloy containing two or more transition metals by irradiating a mixture containing two or more transition metal compounds with light. The inventors have found a manufacturing method and have completed the present invention. The present invention will be described in detail below.

The transition metal compound has a vapor pressure ratio at room temperature.
Higher transition metal carbonyl compounds, metallocenes, metals
Alkoxides can be used. For example, Fe
(CO) _Five, Fe₂(CO)₉, Fe₃(CO)₁2, ferrocene,
(η^Four-(CH₂= CH-CH = CH₂) Fe (CO)₃, Fe (OC
4H₉) 3, Ni (CO)_Four, Co (CO)₃(NO), Cr (CO)
₆, Mo (CO)₆, W (CO)₆, Mn (η^Five-C5H_Five) (C
O)₃, Mn₂(CO)₁For example, 0. Among transition metal compounds
, Transition metal carbonyls are preferred. This is the transition money
The genus carbonyl has a relatively high vapor pressure,
Easy to use, decomposition products other than transition metal atoms are carbon monoxide
(CO) due to the relatively low reactivity of CO
ing. If the vapor pressure of the transition metal compound is not sufficient at room temperature
If this is the case, heat the irradiation container to raise the temperature inside the container.
May increase the vapor pressure.

In the method of the present invention, the above transition metal
Two types of compounds containing different transition metals
Use more. Senki metal compound is introduced in the form of gas
Even if it is adsorbed to the carrier gas and introduced as a mist
You may. The total pressure of the transition metal compound used is 0.1
-100 Torr is preferred. Total pressure is less than 0.1 Torr
And that transition metal alloys cannot be obtained in sufficient yield.
If the total pressure is higher than 100 Torr, the
The question that each reaction does not occur by optical excitation
Subject is likely to occur. 5 to 20 Torr in the above pressure range
Particularly preferred. The ratio of two or more transition metal compounds is
The alloy being made is adjusted to have the desired molar ratio.
It At that time, the composition of the transition metal compound used, the transition metal
Consider the vapor pressure of the compound, the photolysis efficiency of the transition metal compound, etc.
Be considered. For example, Fe 0.1 to 99.9% and Co
To produce an alloy containing 0.1-99.9%, F
e (CO) _FiveAnd Co (CO)₃(NO) is 1: 999 to 999:
It is preferred to use it in a ratio of 1. Fe80-99.
Produce an alloy containing 9% and 0.1-20% Cr
Is Fe (CO)_FiveAnd Cr (CO)₆80: 20-99
Preference is given to using a ratio of 9: 1. Fe99-9
Manufacture an alloy containing 9.9% and Mo 0.1-1%
Fe (CO)_FiveAnd Mo (CO)₆To 99: 1 to 99
Preference is given to using a ratio of 9: 1. Fe99-9
Produce an alloy containing 9.9% and W 0.1-1%
Is Fe (CO)_FiveAnd W (CO)₆To 99: 1 to 999: 1
It is preferable to use it in a ratio of.

SF6, SiF4 or the like can be used as the infrared sensitizer. The infrared photosensitizer is preferably used in a proportion of 1 to 500% with respect to the total pressure of the mixture of two or more kinds of transition metal compounds used. 1% of infrared photosensitizer
If it is smaller, the efficiency of infrared multiphoton absorption by the infrared photosensitizer decreases, and thus a problem that a reaction does not occur occurs.
If the ratio of the infrared photosensitizer is more than 500%, the efficiency of energy transfer from the infrared photosensitizer to the transition metal compound is lowered, so that the reaction does not occur and the infrared photosensitizer is also used. The problem of disassembly arises. 10 of the above ranges
-100% is especially preferable.

Further, by introducing a carrier gas into the irradiation container and moving the gas product generated by the photolysis reaction to the carrier gas to collect it, the amount of the transition metal alloy produced can be increased. As the carrier gas, argon gas, helium gas, nitrogen gas, etc., preferably argon gas and helium gas can be used. The amount of carrier gas introduced is 1 to 2000 To
rr is preferred. Introduced amount of carrier gas is 2000 Torr
If it is more than 1 Torr, there is a problem that each reaction does not occur, and if it is less than 1 Torr, there is a problem that it does not act as a carrier gas. 5 to 5 within the above range
00 Torr is particularly preferred. The carrier gas can be introduced before or after the introduction of the raw material mixture, or at the same time.

Two or more kinds depending on the intended transition metal alloy
Selected transition metal compounds to illuminate these raw material mixtures.
Introduce into the spray container. The infrared photosensitizer is a raw material mixture.
Can be introduced into the irradiation container before, after, or at the same time.
Wear. Before introducing the raw material mixture, set the irradiation container to 10^-2Below Torr
Depressurize to. The pressure in the irradiation container is 10^-2Higher than Torr
And the problem that oxygen in the air affects the reaction
Jijiru Irradiation container is 10 ^-FourMore than Torr
preferable. For the irradiation container, use materials such as glass and metal.
It has a cylindrical shape, with a spherical part in the center and a cylindrical part at both ends.
What kind of shape other than what kind of structure if it can withstand vacuum
A shaped irradiation container can also be used. Irradiation container
The material, shape, light transmittance, light absorptivity, etc. of transition metal
Affects the shape, structure, texture, composition and distribution of gold.
The method of introducing the raw material mixture into the irradiation container is as follows.
The batch method of encapsulating the compound in the irradiation container or the raw material mixture
A continuous flow method of continuously introducing can be used. Communicating
When the continuous distribution method is adopted, for example, the repetition rate is 1
When performing laser irradiation at 10 Hz
Introducing at a rate of 100 liters / minute to 100 liters / minute
Is preferred. If the introduction speed is faster than this, the amount of unreacted substances increases.
In addition, there is a problem that the yield is reduced.
If the input rate is slow, the product may be
There is a problem of reduced purity and generation of by-products
It Within the above range, 100 ml / min-10
L / min is particularly preferred.

Light is irradiated after or while introducing the raw material mixture. As the irradiation light, infrared laser light, visible laser light, ultraviolet laser light, short wavelength ultraviolet laser light, VUV Raman laser light, and / or XUV solid laser light can be used. When a mixture containing two or more kinds of transition metal compounds is irradiated with light from a laser or a powerful lamp, infrared multiphoton decomposition, dielectric breakdown, thermal decomposition, and ultraviolet photolysis of the above compounds occur, resulting in final formation. Fine particles of transition metal alloy or a thin film of transition metal alloy are produced as a substance. When an infrared photosensitizer is added to the above mixture, infrared laser irradiation causes infrared photosensitized decomposition to produce transition metal alloy fine particles or a transition metal alloy thin film.

When producing a transition metal alloy, the raw material is optimized by optimizing the wavelength, energy, fluence, polarization characteristics, pulse width, irradiation pulse number of the laser or lamp used as a light source and the irradiation container. The reaction, reaction temperature, reaction time, etc. of the gas can be controlled, and as a result, the shape, structure, texture state, composition, distribution, etc. of the transition metal alloy can be controlled.

Regarding the method for producing the transition metal alloy in the present invention, the following five kinds of methods are possible. Fe (CO)
The case of an iron-cobalt alloy using ₅ and Co (CO) ₃ (NO) as raw materials will be described as an example. (1) Infrared multiphoton decomposition Since the photon energy of infrared laser is as low as about 2 kcal / mol, no reaction occurs in the one-photon absorption process.
However, when the gas is irradiated with a strong laser beam from an infrared pulsed laser, the molecule absorbs a large number of infrared photons, becomes a highly vibrationally excited state, and then decomposes. This decomposition
This is called infrared multiphoton decomposition. This reaction has been particularly applied to molecular method isotope separation / enrichment. Fe (CO) ₅ and Co
(CO) ₃ (NO) is absorbed by the stretching vibration mode of the CO ligand at 5 μm, and Fe—C—O and Co—C— at 16 μm.
It has absorption by O bond. Therefore, each infrared multiphoton decomposition can be caused by irradiation of a TEA CO2 laser overtone (wavelength 5 μm) or parahydrogen Raman laser (wavelength 16 μm). Fe (CO) ₅ and Co (C
O) ₃ (NO) is introduced at a total pressure of 0.1 to 20 Torr, energy of 0.1 to 1 J, and fluence of 0.1 to 100 J · c.
m ^-2 , pulse width 50-200ns, pulse repetition rate 0.1
It is preferable to irradiate the laser beam for 10 seconds to 1 hour under the condition of 10 Hz.

As a result, Fe (CO) ₅ and Co (CO)
₃ (NO) is decomposed and finally Fe + 5CO
It becomes Co + 3CO + NO, and iron atoms and cobalt atoms are generated. (2) Dielectric breakdown Lasers marketed as infrared pulse lasers are
It is a TEA CO2 laser that oscillates 10 μm light. F
e (CO) ₅ and Co (CO) ₃ (NO) are both 10 μm
Irradiation with TEA CO2 laser light does not cause infrared multiphoton decomposition because it does not have strong absorption in the region.
However, the TEA CO2 laser is focused and radiated with a laser having a short focal length, and the fluence at the focus is 100
When it is set to several hundred J · cm ⁻² or more, dielectric breakdown of the raw material gas occurs with violent explosion noise and light emission of light near the focal point. As a result, Fe (CO) ₅ and Co (CO) ₃
(NO) decomposed respectively and finally Fe + 5CO and Co
It becomes + 3CO + NO, and iron atoms and cobalt atoms are generated. Fe (CO) ₅ and Co (C
A short pulse and powerful laser having an oscillation line in a region where neither O) ₃ (NO) has absorption can cause dielectric breakdown. Although not a commercially available laser, there are NH3 laser, CF4 laser, deuterium (D2) Raman laser and the like. Laser dielectric breakdown can also be caused by a short pulse, high energy UV laser. In this case, the raw materials Fe (CO) ₅ and Co (CO) ₃ (NO)
Is preferably introduced at a total pressure of 0.1 to 100 Torr.

(3) Infrared photosensitized decomposition As a molecule having a high threshold of laser energy for 10 μm infrared multiphoton decomposition by a TEA CO2 laser, there is SF6 having a high binding energy. Number of Fe (CO) ₅ and Co (CO) ₃ (NO) with SF6 added Torr to 10
When a TEA CO2 laser is irradiated on a mixed gas having a total pressure of about 0 Torr, SF6 absorbs infrared multiphotons to be in a high vibration excited state. Laser light irradiation conditions are energy 0.1 to 1 J, fluence 0.1 to 10 J · cm ^-2 , pulse width 50 to 200 ns, pulse repetition rate 0.1 to 10 Hz.
It is preferable to irradiate for 10 seconds to 1 hour.

SF6 Fe (CO) _{5 in} a high vibration excited state by vibration-vibration energy transfer in the process of infrared multiphoton excitation
And Co (CO) ₃ (NO). Furthermore, the mixed gas finally reaches a thermal equilibrium state by vibration-vibration energy transfer, vibration-translational / rotational energy transfer. SF
6 does not cause infrared multiphoton decomposition, but Fe (CO) ₅ and Co (CO) ₃ have lower bond dissociation energy than SF6.
(NO) decomposition can occur. Fe (CO) ₅ excited by high vibration or heat more than bond dissociation energy
And Co (CO) ₃ (NO) desorbs the ligand to finally become Fe + 5CO and Co + 3CO + NO, and iron atoms and cobalt atoms are generated. On the other hand, SF6 is recovered 100% without any decomposition or reaction. This is due to the SF6 infrared sensitization effect of Fe (CO) ₅ and Co (CO) ₃ (N
O) decomposition.

(4) Pyrolysis Fe (CO) ₅ , Co (CO) ₃ (NO), SF 6 and a mixed gas containing argon or helium as a carrier gas and having a pressure of several hundred Torr to 1 atm are introduced into a reaction vessel. Then, when a continuous wave CO2 laser is irradiated, the infrared ray absorption of SF6 is used as a window for energy injection, and the energy of the source gas is increased by the energy transfer. The irradiation conditions of the laser light are energy 0.1 to 10 J and fluence 0.1 to 2.
Irradiation is preferably performed at 00 J · cm ⁻² , pulse width of 100 ns to 10 μs, and pulse repetition rate of 0.1 to 10 Hz for 10 seconds to 1 hour.

As a result, molecules that are easily decomposed by the source gas are thermally decomposed, and finally Fe + 5CO and Co + 3CO +.
It becomes NO and iron atoms and cobalt atoms are generated. (5) Ultraviolet photolysis Fe (CO) ₅ and Co (CO) ₃ (NO) have ultraviolet absorption on the shorter wavelength side than 300 nm, so an ultraviolet laser (KrF excimer laser (248 nm)) adjusted to the absorption,
ArF excimer laser (193 nm), Nd: YA
4th wave of G laser (266nm) or ultraviolet lamp (mercury lamp (185nm, 254nm emission line), xenon lamp, etc.) with Fe (CO) ₅ and Co (C)
When a source gas composed of O) ₃ (NO) is irradiated, Fe (CO)
₅ and Co (CO) ₃ (NO) absorb light and enter an electronically excited state, through which they undergo photolysis. The pressure of the mixed gas of the raw materials is 0.1 to 100 Torr, and the irradiation conditions of the laser light are as follows.
Energy 0.01-0.5J, fluence 10mJ.
It is preferable to irradiate for 10 seconds to 1 hour at cm ^{−2 to} 10 J · cm ⁻² , pulse width of 10 ps to 100 ns, and pulse repetition rate of 1 to 100 Hz.

In the case of irradiation with a short-pulse, high-intensity ultraviolet laser beam, decomposition due to multiphoton absorption may cause decomposition via a high-electron excited state or decomposition due to multiphoton ionization. In any case, as a result of the decomposition, finally Fe + 5CO and Co
It becomes + 3CO + NO, and iron atoms and cobalt atoms are generated. The number of iron atoms and cobalt atoms produced is determined by the composition ratio of the mixed gas of the raw materials, Fe (CO) ₅ and Co (CO) ₃ (NO).
It depends on the efficiency of decomposition.

As described above, the produced iron and cobalt atoms are cooled by nucleation and crystal growth in the air,
It becomes iron alloy fine particles. Due to high temperature, rapid cooling, particle size effect, etc., 5 high temperature stable phase (γ phase) with particle size of 1 to 50 nm
Iron-cobalt alloy fine particles having 0 to 100% are formed. Similar to the method for producing the γ-phase iron-cobalt alloy,
However, the pressure of the raw material gas, the irradiation container, the conditions of light irradiation, that is, energy, fluence, polarization characteristics, pulse width, pulse repetition rate, irradiation time, etc. are appropriately modified to obtain transition metal alloys of various high temperature stable phases. It can be manufactured stably at room temperature. For example, iron-chromium having 50 to 100% of γ phase,
Iron-molybdenum, iron-manganese, iron-nickel, iron-rhenium, iron-copper, etc. can be produced.

The fine particles and powder of the produced transition metal alloy can be collected by a filter or other collecting device. As the filter, a filter in which several filters each having a pore size of 0.1 μm are stacked and placed on a stainless steel filter holder can be used. As another collector, it is possible to use an impactor or the like that collects fine particles entrained in the gas flow by colliding with a collecting plate inserted perpendicularly to the flow by inertial force. The collector is installed near the gas flow outlet from the irradiation vessel.

When producing a transition metal alloy thin film, a thin film substrate is placed in an irradiation container. The substrate may be made of any material such as plastic, glass, ceramics, metal, semiconductor, and organic matter depending on the purpose of use. A transition metal alloy is produced on the surface of the substrate, or fine particles of the transition metal alloy are adsorbed on the surface of the substrate to produce an iron alloy thin film having a uniform thickness. The composition of the transition metal alloy can be controlled mainly by the composition ratio of the mixed gas of the raw materials. Further, the film thickness and its uniformity can be controlled by appropriately selecting the pressure of the source gas and the conditions of light irradiation.

Ultrafine particles or clusters of a transition metal alloy grow on the surface of the substrate to form a thin film, where the thin film is strongly influenced by the properties of the substrate surface. By subjecting the substrate surface to a surface treatment such as machining or plating in advance, or by heating or cooling the substrate surface,
It is possible to manufacture an alloy thin film that is strongly fixed to the substrate surface. For example, a thin film in which the iron alloy in the high temperature stable phase is stabilized can be manufactured by subjecting the substrate to a plating treatment with a metal having the same crystal structure as the iron alloy in the high temperature stable phase. Alternatively, by heating the temperature of the substrate to 80 to 300 ° C. in advance, an iron alloy thin film that is more strongly adsorbed on the substrate surface can be manufactured.

[0027]

The present invention will be described in more detail with reference to the following examples. The examples are illustrative and do not limit the scope of the invention. (Example 1) Iron-cobalt alloy of γ phase stable at room temperature, causing dielectric breakdown by irradiation of TEA CO 2 laser with binary gas mixture of Fe (CO) ₅ and Co (CO) ₃ (NO) as source gas Ultrafine particles were produced. The details will be described below.

An outline of the apparatus used is shown in FIG. Wave number from pulse oscillation TEA CO2 laser 1 940.55
cm ^-1 (10.6 μm band, P (24)) laser pulse light 2 (pulse energy is about 0.5 J, laser fluence at focus is about 700 J · cm ^-2 , pulse width is 80
ns + 1.3μs, laser repetition rate 0.7H
z) is passed through a diaphragm plate 3 having a diameter of 10 mm, then is strongly focused by a convex lens 4 made of barium fluoride having a focal length of 7.5 cm, and placed in an irradiation container 5 made of Pyrex glass 5To.
Fe (CO) ₅ of rr and Co (CO) ₃ (NO) of 0.5 Torr
The sample gas 6 which is a mixed gas of The irradiation container has a sphere having a diameter of 18 cm and a cylindrical tube having an inner diameter of 2.0 cm. The internal volume of this container is 4117 cm3. Also,
A KBr (or NaCl) window plate 7 is attached to the end of the irradiation container.
Further, because of the method (irradiation method) for irradiating while irradiating the raw material gas in the irradiation container, the inlet 8 for introducing the raw material gas
And an outlet 9 and a collector 10 for the ultrafine particles produced.

When laser irradiation was carried out under these conditions, plasma was generated with a large spark sound near the focal point, ultrafine particles were generated and floated in the irradiation container. As the number of laser pulses increased, ultrafine particles accumulated at the bottom of the container, and after irradiation with laser light for about 1 hour, about 30 to 70 mg of ultrafine iron-cobalt alloy particles were synthesized. After laser irradiation, the residual gas in the container and the generated gas are evacuated and removed, and after filling the container with an inert gas (argon or nitrogen), the ultrafine particles generated in the glove box filled with the inert gas are irradiated in the container. It was taken out of the container and stored in a storage container filled with an inert gas. The sample for analysis was prepared by taking out the sample in the storage container in the air.

The obtained iron-cobalt alloy ultrafine particles were applied to IC
When analyzed by P-emission elemental analysis, the cobalt content was 10 at%. The X-ray diffraction pattern of the iron-cobalt alloy ultrafine particles is shown in FIG. As shown in FIG. 2, the diffraction pattern is mainly composed of diffraction lines of face-centered cubic structure (γ phase) and body-centered cubic structure (α phase) and a small amount of diffraction lines of iron oxide and cobalt oxide. The diffraction angle of the strongest diffraction line (2θ / d
is the diffraction angle (2θ = 43.4) of the diffraction line of γ-iron.
It is located near 0 ± 0.06 °). That is, 2θ
= 42.8 °, which is a low angle shift of about 0.6 °. From these results, it is understood that the produced iron-cobalt alloy ultrafine particles are mainly in the γ phase.

On the other hand, when the α phase in the ultrafine particles is examined,
2θ = 44.66 ± 0.02 ° of α iron, 2θ = 44.72 ° for the α-phase iron-cobalt alloy ultrafine particles,
The difference is within the error range and has hardly changed. This corresponds to the fact that even if about 10 at% of cobalt atoms penetrate into the α iron crystal lattice, the lattice constant hardly changes.

As a result of observing the above iron-cobalt alloy ultrafine particles with a transmission electron microscope (TEM), the shape was spherical. FIG. 3 is a particle size distribution of iron-cobalt alloy ultrafine particles. The average particle size was 80 Å, and the particle size distribution was uniform. FIG. 4 shows that the produced cobalt content is 10
It is the Mossbauer spectrum measured at room temperature by the Mossbauer effect of ⁵⁷ Fe of iron-cobalt alloy ultrafine particles of at%. The absorption peak indicated by the arrow in the center corresponds to the γ-phase iron-cobalt alloy ultrafine particles. The γ-phase iron-cobalt alloy ultrafine particles are in a state where there is no internal magnetic field even at 4.2K and are paramagnetic. Further, the α-phase iron-cobalt alloy ultrafine particles that coexist as a by-product are ferromagnetic, and are stronger than the internal magnetic field of α-iron (Hi = 330 kOersted) due to the incorporation of cobalt (Hi = 343 kOersted).

Next, the raw materials Fe (CO) ₅ and Co (CO) ₃
Iron-cobalt alloy ultrafine particles in which the cobalt content was changed by changing the composition ratio of the mixed gas with (NO) were manufactured. That is, Fe (CO) ₅ and Co (C
The total pressure of the mixed gas consisting of O) ₃ (NO) is kept constant at 10 Torr, and the composition ratio (molar ratio) is changed to [Fe (C
O) ₅ ] / {[Fe (CO) ₅ ] + [Co (CO) ₃ (NO)]} =
Samples of 0.5-1.0 were produced.

The content of iron atoms and cobalt atoms in the produced iron-cobalt alloy ultrafine particles was measured by ICP emission elemental analysis. The relationship between the blended composition and the product composition is shown in FIG. From Fig. 5, when the mol% of Fe (CO) ₅ is 85% or less
(Fe atomic% in ultrafine particles) = (0.95 ± 0.01) ×
The relationship of (mol% of Fe (CO) _{5 in} the mixed gas) is such that when the mol% of Fe (CO) ₅ is 85% or more (Fe atomic% in ultrafine particles) = (1.25 ± 0 .02) × (mol% of Fe (CO) _{5 in} the mixed gas) −25%. This relationship indicates that cobalt is contained as a component of the iron-cobalt alloy ultrafine particles in an amount of about 5% more than the composition ratio of the mixed gas.

The ratio of the γ-phase and α-phase iron-cobalt alloy ultrafine particles was determined from the intensity ratio of X-ray diffraction lines. FIG. 6 shows the ratios of the γ phase and the α phase to the cobalt content. FIG. 7 shows the relationship between the content ratio of cobalt in the ultrafine iron-cobalt alloy particles and the maximum magnetization amount; σ _m (the maximum magnetization amount in an external magnetic field of 10 k Oersted and substantially equal to the saturation magnetization amount). The amount of magnetization was measured using a vibrating magnetometer (trade name VSM-3, manufactured by Toei Industry Co., Ltd.). Cobalt content 5at-13at
Up to about%, σ _m decreases slightly with increasing cobalt content. Further, if the cobalt content is increased to 20 at%, σ _m increases. Thereafter, when the cobalt content is further increased to 35 at%, σ _m is decreased, and when it is increased to 50 at%, σ _m is increased again.

This result almost corresponds to the result of X-ray diffraction. That is, as the γ phase increases, σ _m decreases, and α
Σ _m increases as the number of phases increases. (Example 2) In Example 1, a metal chamber was used as the irradiation container, and a glass substrate (diameter 100 mm, thickness 1.2 mm) for forming a thin film at an arbitrary location inside the irradiation container.
(disc-shaped mm) was installed in the same manner as in Example 1 except that a binary mixture gas of Fe (CO) ₅ and Co (CO) ₃ (NO) was used as a raw material gas by TEA CO 2 laser irradiation for dielectric breakdown. Then, a γ-phase iron-cobalt alloy thin film was produced on the surface of the substrate placed in the container.

An outline of the apparatus used is shown in FIG. It is almost the same as that of the first embodiment, and is provided with an inlet and an outlet for introducing a raw material gas for circulating the raw material gas. Further, since the substrate is installed on the stage whose position and angle can be changed arbitrarily, the distance and angle between the substrate and the laser beam can be set arbitrarily. Further, the temperature of the stage for holding the substrate can be changed from -60 ° C to 300 ° C. In this embodiment, the distance between the substrate and the laser beam is 0.5c.
m, and the substrate stage was set at 150 ° C.

After the same treatment as in Example 1, the substrate was taken out of the irradiation container and subjected to surface analysis by ESCA in addition to ICP emission element analysis, transmission electron microscope observation, X-ray diffraction, Mossbauer spectrum and the like. It was As a result, it was found that this thin film was an iron-cobalt alloy thin film having a uniform thickness of 10 nanometers and containing a γ phase. The pulse energy at this time is about 0.2 J, the laser fluence is about 0.2 J · cm ^-2 , and the pulse width is 80 ns FW.
HM + 1.3μs, laser repetition rate is 0.7H
z. Fe (CO) ₅ and Co (CO) ₃ (NO) and SF
In the region where the composition ratio of 6 is 1: 1: 1 and the total pressure is in the range of 10 to 50 Torr, the γ-phase iron-cobalt alloy is mainly produced by SF6 infrared photosensitized decomposition, and the inert gas (helium, argon) is added to the ternary mixed gas. Etc.) and the total pressure is set to several hundred Torr, the α-phase iron-cobalt alloy is mainly produced by thermal decomposition. (Example 3) In Example 1 and Example 2, as a raw material gas, a three-component mixed gas of Fe (CO) ₅ , Co (CO) ₃ (NO) and SF6 (mixing ratio 5 to 15: 1: 3 to 20). , Total pressure 5 to 20 Torr), and iron-cobalt alloy ultrafine particles and a thin film were manufactured by the same method as in Examples 1 and 2 except that the TEA CO2 laser was irradiated with parallel light without focusing with a lens. . (Example 4) In Example 1 and Example 2, a mixed gas obtained by adding 10 to 500 Torr of argon as an inert gas to two components of Fe (CO) ₅ and Co (CO) ₃ (NO) as a source gas. Example 1 and Example 2 except that it was used and irradiated with parallel light using an ArF excimer laser instead of a TEA CO2 laser (ultraviolet photolysis).
An iron-cobalt alloy ultrafine particle and a thin film were respectively manufactured by the same method as described above.

The pulse energy at this time is about 0.1 J,
Laser fluence is about 0.2Jcm ^- 2, pulse width 2
0ns FWHM, laser repetition rate is 30Hz
And The composition of the iron-cobalt alloy depended on the pressure and composition of the raw material gas and the laser irradiation conditions, but the amount of γ phase produced was about 10 to 60 at% in terms of composition ratio, which was mainly the same as when using an infrared laser. γ-phase iron-cobalt alloy ultrafine particles and thin films were obtained. (Embodiment 5) Similar to Embodiments 2, 3 and 4, except that an aluminum substrate plated with copper having a face-centered cubic structure at room temperature is used as the substrate. The method produced an iron-cobalt alloy thin film.

By this method, a γ-phase iron-cobalt alloy thin film was obtained mainly. Example 6 An iron-cobalt alloy thin film was manufactured in the same manner as in Examples 2, 3 and 4, except that the temperature of the substrate was maintained at 100 ° C. in Examples 2, 3 and 4. By this method, a γ-phase iron-cobalt alloy thin film was obtained mainly. (Example 7) In Example 1, 8 Torr was used as a raw material gas.
Γ-phase iron-chromium alloy ultrafine particles were produced in the same manner as in Example 1 except that a mixed gas of Fe (CO) ₅ and 0.5 Torr of Cr (CO) ₆ was used.

The obtained iron-chromium alloy ultrafine particles were subjected to ICP.
When analyzed by light emitting elemental analysis, the chromium content was 6 at%. The X-ray diffraction pattern of the iron-chromium alloy ultrafine particles is shown in FIG. As shown in FIG. 9, the diffraction pattern is mainly composed of a face-centered cubic structure (γ phase) and a body-centered cubic structure (α phase).
Phase) and a small amount of iron oxide and chromium oxide diffraction lines. The diffraction angle of the strongest diffraction line is almost the same as the diffraction angle of the diffraction line of γ-iron (2θ = 43.40 ± 0.06 °). . The diffraction angles of other diffraction lines are 2θ = for α iron.
Since it coincided with 44.66 ± 0.02 °, it was found to be an α-phase iron-cobalt alloy ultrafine particle. That is,
Even if about 6 at% of chromium atoms penetrate into the iron crystal lattice,
It can be seen that the diffraction angle of the diffraction line does not change much. The ratio of the iron-chromium alloy ultrafine particles of the γ phase and the α phase was γ phase: α phase = 63: 37 when calculated from the intensity ratio of X-ray diffraction lines.

Next, as a result of observation with a transmission electron microscope,
The iron-chromium alloy ultrafine particles are spherical and have an average particle size of 10
At 0 Å, the particle size distribution was uniform. When the magnetism of the obtained iron-chromium alloy ultrafine particles having a chromium content of 6 at% was measured, the maximum magnetization amount σ _m = 9.4 emu.
/ G, and a coercive force H _c = 200 Oe. (Example 8) In Example 1, 8 Torr was used as a source gas.
Γ-phase iron-molybdenum alloy ultrafine particles were manufactured in the same manner as in Example 1 except that a mixed gas of Fe (CO) ₅ of No. ₅ and Mo (CO) ₆ of 0.05 Torr was used.

The obtained iron-molybdenum alloy ultrafine particles were added to I
When analyzed by CP emission elemental analysis, the molybdenum content was 0.6 at%. The X-ray diffraction pattern of the ultrafine iron-molybdenum alloy particles is shown in FIG. As shown in FIG. 10, the diffraction pattern is mainly composed of diffraction lines of face-centered cubic structure (γ phase) and body-centered cubic structure (α phase) and a small amount of diffraction lines of iron oxide and chromium oxide. The diffraction angle of the strongest diffraction line is the diffraction angle of the diffraction line of γ-iron (2θ = 43.40 ± 0.0
6 °) is almost the same (43.33 °), which is due to the γ-phase ultrafine particles of iron-molybdenum alloy, which is originally a stable phase at high temperature. The diffraction angles of other diffraction lines are 2θ of α iron = 44.66 ±
Since it coincided with 0.02 °, it was found that the particles were α-phase iron-molybdenum alloy ultrafine particles. That is, it can be seen that the diffraction angle of the diffraction line does not change much even if about 0.6 at% of molybdenum atoms penetrate into the iron crystal lattice. The ratio of the γ-phase and α-phase ultrafine iron-molybdenum alloy particles was γ phase: α phase = 7: 3 when calculated from the intensity ratio of X-ray diffraction lines.

Next, as a result of observation with a transmission electron microscope (TEM), the ultrafine iron-molybdenum alloy particles are spherical,
The average particle size was 100 Å, and the particle size distribution was uniform. The magnetism of the obtained iron-molybdenum alloy ultrafine particles having a molybdenum content of 0.6 at% was measured.
_m = _26.9emu / g, was H _c = 250 Oe. (Example 9) In Example 1, 8 Torr as a source gas
Γ-phase iron-tungsten alloy ultrafine particles were produced in the same manner as in Example 1 except that a mixed gas of Fe (CO) ₅ of No. ₅ and W (CO) ₆ of 0.05 Torr was used.

When the obtained iron-tungsten alloy ultrafine particles were analyzed by ICP emission elemental analysis, the tungsten content was 0.6 at%. The X-ray diffraction pattern of the iron-tungsten alloy ultrafine particles is shown in FIG.
As shown in FIG. 11, the diffraction pattern is mainly composed of diffraction lines of face-centered cubic structure (γ phase) and body-centered cubic structure (α phase) and a small amount of diffraction lines of iron oxide and chromium oxide. The diffraction angle of the strongest diffraction line is the diffraction angle of the diffraction line of γ-iron (2θ = 43.4).
It is almost the same as 0 ± 0.06 ° (43.26
°), due to gamma-phase iron-tungsten alloy ultrafine particles, which is originally a stable phase at high temperature. The diffraction angles of other diffraction lines are 2θ of α iron.
= 44.66 ± 0.02 °, so α-phase iron −
It was found to be ultrafine tungsten alloy particles. That is, it can be seen that the diffraction angle of the diffraction line does not change much even if about 0.6 at% of tungsten atoms penetrate into the iron crystal lattice. The ratio of the iron-tungsten alloy ultrafine particles in the γ phase and the α phase is calculated from the intensity ratio of X-ray diffraction lines, and the γ phase: α
Phase = 4: 1.

Next, as a result of observation with a transmission electron microscope (TEM), the ultrafine iron-tungsten alloy particles were spherical, the average particle size was 100 Å, and the particle size distribution was uniform. The obtained tungsten content rate is 0.6 at
%, The magnetism of the ultrafine iron-tungsten alloy particles was measured and found to be σ _m = 9.4 emu / g and H _c = 150 oersted.

[0047]

According to the method for producing a transition metal alloy of the present invention, an alloy of a transition metal and an arbitrary metal can be produced. Further, according to the method of the present invention, it is possible to manufacture a fine particle having a particle diameter of about 10 nm and a uniform particle diameter, and a transition metal alloy having a uniform thin film shape having a thickness of about nanometer.

Further, according to the method of the present invention, it is possible to produce a transition metal alloy having a high temperature stable phase and a novel transition metal alloy which cannot be produced by the conventional method. For example, the method of the present invention can produce a transition metal alloy having properties such as structure and magnetism that are different from those of a conventional transition metal alloy produced by a conventional method. The transition metal alloy produced by the method of the present invention is used for a new magnetic material, sensor, memory, composite material, etc., and also because the shape of the transition metal alloy is ultrafine particles or a thin film, it can be used for catalyst, sintering, electron There are potential applications in many fields such as materials.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus used in Example 1 of the present invention.

FIG. 2 is a table showing an X-ray diffraction pattern of iron-cobalt alloy ultrafine particles obtained in Example 1 of the present invention.

FIG. 3 is a table showing the particle size distribution of iron-cobalt alloy ultrafine particles obtained in Example 1 of the present invention.

FIG. 4 is a chart showing a ⁵⁷ Fe Moessbauer spectrum at room temperature of iron-cobalt alloy ultrafine particles obtained in Example 1 of the present invention.

FIG. 5 shows the content of iron atoms and cobalt atoms in the iron-cobalt alloy ultrafine particles obtained in Example 1 of the present invention and the composition ratio ([Fe (CO) ₅ ] in the mixed gas of the raw materials. / ([Fe (C
O) ₅ ] + [Co (CO) ₃ (NO)])).

FIG. 6 is a chart showing the relationship between the composition ratio of the γ phase and the content of cobalt atoms in the iron-cobalt alloy ultrafine particles obtained in Example 1 of the present invention.

FIG. 7 is a chart showing the relationship between the saturation magnetization and the content of cobalt atoms in the iron-cobalt alloy ultrafine particles obtained in Example 1 of the present invention.

FIG. 8 is a schematic view of an apparatus used in Example 2 of the present invention.

FIG. 9 is a table showing an X-ray diffraction pattern of iron-chromium alloy ultrafine particles obtained in Example 7 of the present invention.

FIG. 10 shows the iron-obtained in Example 8 of the present invention.
4 is a chart showing an X-ray diffraction pattern of molybdenum alloy ultrafine particles.

FIG. 11 shows the iron obtained in Example 9 of the present invention.
4 is a chart showing an X-ray diffraction pattern of ultrafine tungsten alloy particles.

[Explanation of symbols]

1 CO 2 pulse laser, 2 laser light 3 diaphragm plate 4 BaF ₂ lens 5 irradiation container (cylindrical Pyrex glass or metal chamber) 6 sample gas 7 KBr or NaCl window plate 8 gas inlet port 9 gas outlet port 10 ultrafine particles Collector 11 Temperature variable stage for substrate installation 12 Substrate for thin film formation

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location C23C 16/48 7325-4K (72) Inventor Tetsusu Miyahara 1550-2-2, Rokuzaki, Sakura City, Chiba Prefecture −104

Claims (11)

[Claims] 1. A method for producing an alloy containing two or more transition metals by irradiating a mixture containing two or more transition metal compounds with light. 2. The method according to claim 1, wherein the mixture is in a gaseous state. 3. The alloy produced has a γ phase.
The method described. 4. The method according to claim 1, which comprises an iron compound as the transition metal compound. 5. The method according to claim 1, wherein the infrared photosensitizer is added to the mixture containing two or more kinds of transition metal compounds. 6. The method according to claim 1, wherein the irradiation light is infrared laser light, visible laser light, ultraviolet laser light, short wavelength ultraviolet laser light, VUV Raman laser light and / or XUV solid laser light. 7. The method according to claim 1, wherein the alloy produced has the form of fine particles, powder or a thin film. 8. The method according to claim 7, wherein a substrate is placed in a reaction vessel, and fine particles, powder or thin film of a transition metal alloy is deposited on the surface of the substrate. 9. The method according to claim 7, wherein the substrate is surface-treated by machining or plating in advance. 10. The substrate surface is heated or cooled.
The method described. 11. A transition metal alloy particle or thin film obtained by the method according to claim 1.