JPS6230831A - Spectral reflectance-variable alloy and recording material - Google Patents

Abstract

PURPOSE:To obtain an alloy having partially different spectral reflectances at the same temp. by preparing an alloy having silver as a principal component, containing specific amounts of specific elements such as zinc, Cd, etc., and having a spectral reflectance which differs according to the methods of cooling. CONSTITUTION:The alloy having silver as a principal component and containing 30-46wt% Zn, <=10wt% Cd and <=15wt% of 1 or >=2 elements among the elements of groups Ia, IIa, IVa, Va, VIa, VIIa, VIII, Ib, IIIb, IVb and Vb and rare earth elements is prepared. In this alloy, the crystal structure in a condition of primary temp. (high temp.) higher than room temp. differs from that in a condition of a temp. (low temp.) lower than the primary temp. in the form of solid. Therefore the spectral reflectance in the case where a high-temp. phase is cooled rapidly differs from that in the case of a low-temp. phase of normal condition unsubjected to rapid cooling, so that the spectral reflectance changes reversibly according to heating and rapid cooling in a temp. region of high-temp. phase and heating and cooling in a temp. region of low-temp. phase. Further, the difference in the spectral reflectance is >=5% and it is preferable to use nonbulk material as the above alloy.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a novel alloy with variable spectral reflectance and a recording material, and in particular to a novel alloy with variable spectral reflectance and a recording material, and in particular, the spectral reflectance of the alloy changes as the crystal structure of the alloy changes due to the application of light and thermal energy. This invention relates to alloys that can be used as media for information recording, display, sensors, etc. that utilize change.

[Background of the invention]

In recent years, as information recording becomes more dense and digital, various information recording and reproducing methods are being developed. In particular, optical discs that use laser light energy for recording, erasing, and reproducing information are manufactured using industrial rare metal N1180.1983.
As described in (Optical Disks and Materials), higher recording densities are possible than magnetic disks, and this will be a promising method for information recording in the future. Among these, laser playback devices have been put into practical use as compact discs (CDs). On the other hand, recordable methods can be broadly divided into two types: write-once type and rewritable type. The former can only be written once and cannot be erased. The latter is a method that allows repeated recording and erasing.

In the write-once type recording method, a laser beam destroys or forms the recording area of the medium to make it uneven, and for reproduction, the change in the amount of light reflection due to the interference of the laser beam on the uneven area is used. It is generally known to form irregularities by melting and sublimating Te or its alloys. This type of medium has some problems such as toxicity. Magneto-optical materials are the mainstream for rewritable recording media.

This method utilizes optical energy to invert and record the local magnetic anisotropy of the medium near the Curie point or compensation point temperature, and the polarization plane of the polarized incident light at that part due to the magnetic Faraday effect and magnetic effect. Play with the amount of rotation. This method is considered to be the most promising rewritable method, and active research and development is underway with the aim of putting it into practical use in the next few years.

However, there is currently no material with a large amount of rotation of the plane of polarization, and even with various measures such as multilayer film formation, there is a big problem that output levels such as S/N and C/N are low. Other rewritable systems utilize reflectance changes due to reversible phase changes between amorphous and crystalline recording media. For example, the National Technical Report (Nati
onal Technical Report) Vo
There is an alloy in which small amounts of Ge and Sn are added to TeOx described in Q 29 Na 5 (1983).

However, this method has a major problem in that the crystallized portion of the amorphous phase is low and the instability of the phase at room temperature affects the reliability of the disk.

On the other hand, as an alloy utilizing color tone change, JP-A-57-1
There are 40845. This alloy is (12-15)wt%A
Q, -(1 to 5) wt% This is an alloy consisting of Ni and residual Cu, which takes advantage of the fact that it changes reversibly from red to gold at the martensitic transformation temperature. Martensitic transformation is a transformation that inevitably occurs as the temperature decreases, so the color tone obtained when the temperature is maintained above the martensitic transformation temperature cannot be brought below the martensitic modulation temperature, and conversely, the martensitic transformation If a color tone obtained at a temperature below this temperature is heated above the martensitic transformation temperature, the color tone will undergo transformation and change to a different color tone. Therefore, the two color tones that occur during the upper stage of martensitic transformation cannot be obtained simultaneously at the same temperature.
Therefore, this principle cannot be applied as a recording material.

[Purpose of the invention]

An object of the present invention is to provide a variable spectral reflectance alloy and a recording material that can maintain partially different spectral reflectances at the same temperature.

[Summary of the invention]

The main component of the present invention is 1A, 2A and 4A, with silver as the main component, 30 to 46% zinc and 10% or less cadmium by weight.

5A, 6A, 7A, 8. IB, 2B, 3B, 4B.

The variable spectral reflectance alloy is characterized by being made of an alloy containing 15% by weight or less of one or more of group 5B and rare earth elements in total.

That is, the present invention provides a first temperature higher than room temperature (
An alloy having different crystal structures at a temperature lower than the first temperature (high temperature) and at a temperature lower than the first temperature (low temperature), characterized in that the alloy has a crystal structure different from that obtained by non-quenching at the low temperature due to quenching from the high temperature. It is an alloy with variable spectral reflectance.

The alloy of the present invention has at least two types of spectral reflectance at the same temperature by heating and cooling treatment in a solid state, and the spectral reflectance can be changed reversibly. That is, the alloy according to the present invention has phases with different crystal structures in at least two temperature ranges in a solid state, and among these, the high temperature phase is quenched and the low temperature phase is a non-quenched standard state. The spectral reflectance is different, and the spectral reflectance changes reversibly by heating and cooling in a high sum temperature range and heating and cooling in a low sum temperature range.

The principle of the reversible change in reflectance of the alloy of the present invention will be explained using FIG. 1. FIG. 0 is a phase diagram of an X-Y binary alloy, in which an α solid solution and β, γ intermetallic compounds are present. Taking an alloy with composition A as an example, in the in-phase state, this alloy has
There are β single phase, (β+γ) phase and (α+γ) phase. The crystal structure is α, β.

The single phase state of γ is different, and the optical properties, such as spectral reflectance, are different in these single phase and mixed phase. Such an alloy has a T1 temperature.

Generally, the (α+γ) phase is stable at room temperature. When this is heated and rapidly cooled to T4 temperature, the β phase is rapidly cooled to T4 temperature. Since this state is different from the (α+γ) phase, the spectral reflectance is also different. When this rapidly cooled β-phase alloy is heated and cooled to a temperature T below the TO temperature, the β phase transforms into an (α+γ) phase, and the spectral reflectance returns to its initial state. 2 like this
By repeating two heating and cooling processes, it is possible to reversibly change the spectral reflectance.

(Alloy Composition) The alloy of the present invention has different crystal structures at high and low temperatures, and the rapidly cooled crystal structure must be formed by rapid cooling from a high temperature. Furthermore,
The phase formed by this rapid cooling must be able to change into a crystalline structure at a low temperature by heating at a predetermined temperature.

From these points of view, silver is the main component, and zinc is 30 to 4 by weight.
An alloy composition containing 6% and 10% or less of cadmium is preferred. Cd is in the A E -Z n = elemental system, and when the amount of Zn is 36% or less, the β' phase (pink color) changes to the β' → ξ phase due to changes over time. The pink color turns silvery white. Adding Cd has the effect of preventing this change over time. The amount of Cd is particularly preferably 1.5 to 7.5% by weight.

Furthermore, the high-temperature intermetallic compounds are stable and the temperature at which the spectral reflectance changes, that is, the in-phase transformation point, can be controlled arbitrarily depending on the application, such as 1A or 2A.

4A, 5A, 6A, 7A, 8. IB, 3B, 4B.

An alloy containing a total of 15% by weight or less of one or more of Group 5B elements and rare earth elements is good. Specifically, Group IA elements include lithium, Group 2A elements include magnesium and calcium, Group 4A elements include titanium, zirconium, and hafnium, Group 5A elements include vanadium, niomium, and tantalum, Group 6A elements include chromium, molybdenum, and tungsten, and Group 7A elements include manganese. Group 8 is cobalt, rhodium, iridium, iron, ruthenium, osmium, nickel, palladium, platinum, I
Group B is copper, silver, and gold; group 3B is boron, aluminum, gallium, and indium; and group 4B is carbon.

Silicon, germanium, tin, button, and group 5B is phosphorus.

Antimony, bismuth, rare earths include yztrium,
Particularly preferred are lanthanum, cerium, samarium, gadolinium, terephium, dysprosium, and lutetium.

(Non-bulk and manufacturing method thereof) In order to obtain reflectance variability, the alloy of the present invention must be able to form a supercooled phase by heating and rapidly cooling the material. In order to create and store information at high speed, it is desirable to use a non-bulk material with a high rapid heating and cooling effect and a small heat capacity. That is, it is desirable to be a non-bulk material having a volume that allows substantially only a desired area portion to be changed to a crystal structure different from a reference crystal structure throughout the depth by energy input to a desired minute area. Therefore, in order to produce high-density information in a desired micro area, it is desirable to use non-bulk materials such as foils, films, thin wires, or powders, which have a small heat capacity. 0.01-0.2μ for the production of information.
It is preferable to set the film thickness to m. Generally, intermetallic compounds are difficult to plastically work.

Therefore, it is effective to directly rapidly cool and solidify the material from the gas phase or liquid phase to form it into a predetermined shape as a method for producing foil, film, thin wire, or powder. These methods include PVD methods (vapor deposition, sputtering methods, etc.).

There are CVD methods, molten metal quenching methods in which molten metal is rotated at high speed and made of a member with high thermal conductivity, and in particular, molten metal is poured onto the circumferential surface of a metal roll and rapidly solidified, electroplating, and chemical plating methods. When using a film or powder material, it is effective to form it directly on the substrate or to coat it and adhere it to the substrate.7 When coating, the powder does not cause any reaction even when heated. ) A binder is better. Furthermore, in order to prevent oxidation of the material due to heating, it is also effective to coat the surface of the material, the film formed on the substrate, or the surface of the coating layer.

The foil or thin wire is preferably formed by a molten metal quenching method, and preferably has a thickness or diameter of 0.1 mm or less.

In particular, a thickness or diameter of 0.05++n or less is preferred for producing foils or fine wires with grain sizes of 0.1-μm or less.

The powder is preferably formed by the Gaia 1-Mize method, in which molten metal is sprayed together with a gaseous or liquid refrigerant and then poured into water to be rapidly cooled. The particle size is preferably 0.1 mm or less, and ultrafine powder with a particle size of 1 μm or less is particularly preferable.

The film can be formed by vapor deposition, sputtering, CVD electroplating, chemical plating, etc., as described above.

In particular, sputtering is preferred for forming a film thickness of 0.1 μm or less. Sputtering allows easy control of the target alloy composition.

(Group 5) The alloy of the present invention must have a different crystal structure at high and low temperatures, and must have a composition of a subcooled phase in which the crystal structure at high temperature is maintained at low temperature by rapid cooling from high temperature. It has an irregular lattice crystal structure, but
There are m rapid cooling phases! - An intermetallic compound having a regular lattice is preferable. Since the alloy of the present invention can greatly change optical properties, it is preferable that the alloy mainly forms this intermetallic compound, and particularly preferably has a composition in which the entire alloy forms an intermetallic compound. These intermetallic compounds are called electronic compounds, especially 3/2 electron compounds (average outer shell electron concentration e
/a is 3/2) alloy composition is good.

Further, the alloy of the present invention preferably has an alloy composition having solid phase transformation, particularly eutectoid transformation or enveloping transformation, and the alloy can be obtained with a large difference in spectral reflectance by quenching from high temperature and non-quenching.

The alloy of the present invention preferably has ultrafine crystal grains, and particularly preferably has a crystal grain size of 0.1 μm or less.

That is, the crystal grains are preferably smaller than the wavelength of visible light, but may be smaller than the wavelength of semiconductor laser light.

In addition, since the heat capacity of the film formed on the substrate is reduced, the film can be divided into the minimum size of the recording unit by etching or the like.

(Characteristics) The variable spectral reflectance alloy and recording material of the present invention can form at least two types of spectral reflectance in the visible light region at the same temperature. That is, it is necessary that the spectral reflectance of a material having a crystal structure (tissue) formed by rapid cooling from a high temperature is different from that of a material having a crystal structure (group m) formed by non-quenching.

Further, the difference in spectral reflectance obtained by quenching and non-quenching is preferably 5% or more, particularly preferably 10% or more. If the difference in spectral reflectance is large, it will be easy to visually identify the color, and it will have a remarkable effect in various applications described later.As a light source for spectral reflection, electromagnetic waves other than visible light can be used. , infrared rays, ultraviolet rays, etc. can also be used.

Other properties of the alloy of the present invention include electrical resistivity, light refractive index, light polarization rate, light transmittance, etc., which can be reversibly changed in the same way as spectral reflectance. It can be used as a means for recording, reproducing, erasing and displaying various information such as, reproducing and detecting sensors, etc.

Since the spectral reflectance is related to the surface roughness of the alloy, it is preferable that at least the intended portion has a mirror surface so as to have 10% or more in the visible light region as described above.

(Applications) The alloy of the present invention can be heated and rapidly cooled to partially or entirely change its physical or electrical properties such as spectral reflectance of electromagnetic waves, electrical resistivity, refractive index, polarization index, and transmittance due to a change in crystal structure. By utilizing changes in these characteristics, it can be used for elements such as recording, display, and sensors.

Electric energy in the form of voltage and current, electromagnetic waves (visible light, radiant heat) are used as a means of recording information, etc.

Infrared, ultraviolet, photographic flash lamp light, bundle beam,
A proton beam, an argon laser, a laser beam such as a semiconductor laser beam, heat, etc.) can be used, and it is particularly preferable to utilize the change in spectral reflectance caused by the irradiation in the recording medium of an optical disk. Optical discs include digital audio discs (DAD or Combat L-discs), video discs, memory discs, and the like, and can be used for these. By using the alloy of the present invention in the recording medium of an optical disc, it is possible to create a read-only type and an additional recording type.

It can be used in any rewritable disk device, and is particularly effective in rewritable disk devices.

An example of the principle of recording and reproduction when the alloy of the present invention is used in a recording medium of an optical disk is as follows.

First, the recording medium is locally heated and then rapidly cooled to maintain the crystal structure in the high temperature region in the low temperature region to record predetermined information, or the high temperature phase is used as a base to locally heat the recording medium. recorded by locally low-temperature phases during high-temperature heating,
Information can be reproduced by irradiating the recorded area with light and detecting the difference in optical characteristics between the heated area and the non-heated area. Information written on it can be erased by heating it. The light is preferably a laser beam, particularly a short wavelength laser. The reflectance of the heated portion and non-heated portion of the present invention is 500 nm or 8o.

It is largest at wavelengths around nm, so 1. It is preferable to use a laser beam having a wavelength like 2 for reproduction. The same source is used for recording and playback.

For erasing, it is preferable to irradiate another laser beam with a lower energy density than that for recording.

Also, the alloy of the present invention! 8@ The disk used as the medium has the great advantage of being able to visually determine whether or not information is recorded.

Since the display can partially change the spectral reflectance of visible light, it is possible to record characters, figures, symbols, etc. without using paint, and these displays can be visually identified. I can do it. Furthermore, this information can be erased, and in addition to being used repeatedly by recording and erasing, it is also possible to store it permanently. Examples of its applications include clock faces and accessories.

As a sensor, there is a temperature sensor that utilizes changes in spectral reflectance, especially in visible light. A sensor using the alloy of the present invention, whose temperature at which it changes to a high-temperature phase is known in advance, is held in the temperature range to be measured.

Approximate temperature detection can be performed by maintaining an appropriate cooling phase through appropriate cooling.

(Production method) The present invention provides a first temperature higher than room temperature in a solid state and a first temperature higher than room temperature in a solid state.
A part of the surface of the alloy having the chemical composition described above, which has a crystal structure different from that at the second temperature lower than the temperature, is rapidly cooled from the first temperature to form a crystal structure different from the crystal structure at the second temperature. and forming a region having a crystal structure formed by the rapid cooling and forming a different spectral reflectance between the region having the crystal structure formed by the rapid cooling and the region having the crystal structure at the second temperature. It is in the manufacturing method of the alloy.

Furthermore, one aspect of the present invention provides that the entire surface of the alloy having the aforementioned chemical composition having a different crystal structure at a first temperature higher than room temperature and a second temperature lower than the first temperature in a solid state is heated at the first temperature. to form a crystal structure different from the crystal structure at the second temperature, and then heat a portion of the alloy surface to the second temperature to form a region having the crystal structure at the second temperature. and forming different spectral reflectances in the region having the crystal structure formed by the rapid cooling and the region having the crystal structure at the second temperature. be.

The cooling rate from the first temperature is preferably 10''C/sec or more, more preferably 103C/sec or more.

[Embodiments of the invention]

[Example] - A g -35 wt% Zn-Cd alloy was formed into a foil shape by a molten metal quenching method, and its color change, 1-spectral reflectance, etc. were investigated. Zn 35 wt%, 1.7 in Ag.

Alloys containing 2.8, 3.5, and 7.0 wt% were melted in an argon atmosphere and solidified into a rod shape of about 4 mm diameter. This was cut into pieces with a weight of about 5 to Log to prepare a mother alloy for rapidly cooling the molten metal.

For the molten metal quenching method, the master alloy is charged into a quartz nozzle using a generally known ridge roll type device, remelted, and poured onto the outer periphery of a roll (300 mφ) rotating at high speed to a thickness of 50 μm.
An AgZn-Cd alloy foil with a width of 5 m was produced. This foil was heated in an electric furnace for 2 minutes at each temperature, then cooled with water, and the color change and spectral reflectance of the foil were measured. Figure 2 shows the color change of the foil after heating and quenching; the * mark is pink and the 0 mark is silvery white.

The boundary of color change in the Ag-35%Zn alloy that does not contain Cd is 275°C, and this temperature hardly changes even if Cd is added.

Figure 3 shows the color of the pink foil when it was heat treated at temperatures below 200°C for 2 minutes and then air cooled.

The temperature at which the Cd-free Ag-35%Zn alloy changes from pink to silvery white is approximately 135°C;
This temperature does not change even if is added. The above color change is caused by the β′ phase, which causes the pink color due to rapid cooling from high temperature.
The change from pink to silvery white is thought to be due to β'→ζ transformation.

Figure 4 shows 1 of Ag-35%Zn-3,5%Cd alloy foil.
The spectral reflectance after 00h has passed is shown. 450 and 600n
A remarkable difference in reflectance is observed except in the m wavelength region. The color change between pink and silvery white as described above occurs at 350℃ and 2
Changes reversibly by repeating heating and cooling at 00℃,
Along with this, the spectral reflectance also changed almost reversibly.

Furthermore, when the silver-white foil was locally heated and rapidly cooled with a lighter, only those areas became pink, and the boundaries between the colors were very clear. Conversely, when the pink foil was locally heated, some parts became silvery white.

Figure 5 shows the difference in the spectral reflectance of the Ag-35Zn binary alloy and the Ag35Zn-3,5Cd alloy of the present invention in the 830 nm wavelength region between the pink foil and the silver-white foil over time. This is what is shown. C
In the case of the Ag-35Zn binary alloy that does not contain d, the difference in spectral reflectance becomes smaller over time.

This is because the β' phase (pink color) due to heating and rapid cooling changes from pink to silvery white over time, and the difference in spectral reflectance with the silvery white foil becomes smaller.

On the other hand, the Ag-35Zn-3,5Cd alloy to which Cd is added does not change over time and exhibits the effect of Cd.

[Example 2] A, g -35%Zn-3,5%Cd alloy was melted in an argon atmosphere and solidified into a cylindrical shape of about 1.20 wrφ. A disk with a thickness of 5 wi and a diameter of 100 mm was cut out from this and used as a target for sputter deposition.

As the sputter deposition method, a DC-magnetron type was used, and the above alloy was sputter-deposited to a thickness of about 80 nm using a hard glass of about 26++ mφ and 1.2 m thick as the substrate, and the substrate temperature was 200° C. and the sputter power was 150 mW. Ar gas at 20 m Torr was used as the gas. The film surface is further coated with Al220. by RF sputtering. or Sin
, was deposited as a protective film to a thickness of about 20 nm.

In the sputter-deposited state, the film was silvery white. When the film was heat-treated together with the substrate at 350° C. for 2 minutes and then cooled with water, it turned pink. When this was further heat-treated under the same conditions at 20° C., the color returned to silvery white. In this way, the sputtered film also showed the same color change as the foil.

[Example 3] Ag-35%Zn-3 produced by the same method as Example 2
, 5%Cd sputtered film was subjected to recording, reproduction, and erasing using a laser beam. As a laser beam, a semiconductor laser (wavelength 830 nm) or an Ar laser (wavelength 488 nm) is used.
was used. The power of the laser beam is 10 to 50 mW at the film surface.
By changing the beam diameter from about 1 .mu.m to about i-0 .mu.m and scanning the silvery-white film surface, a line that turned pink could be drawn. This line width depends on the laser output, approximately 1
It was possible to vary from μm to 20 μm. When several such lines were drawn and a semiconductor laser was scanned across the lines, the change in reflectance enabled the color change to be converted into an electrical signal as a change in the DC voltage level of approximately 20%.

The lines drawn in this way could be easily restored to their original silvery white color by heating the entire film to nearly 200°C or by scanning it with a laser beam of low power density.

〔Effect of the invention〕

According to the present invention, the color or spectral reflectance due to crystal-crystal phase transition can be reversibly changed, so that a remarkable effect can be obtained in which recording and erasing can be performed as an information recording medium.

[Brief explanation of drawings]

Figure 1(a) is an equilibrium phase diagram of the A g -Z n binary system, Figure 1(b) is a diagram of the principle of recording and erasing by the heating and quenching process of the alloy of the present invention, and Figures 2 and 3 are the diagram of the book. Invention of molten metal quenching A
Figure 4 shows the color change of g-Z-n-Cd alloy foil due to heat treatment.
, A diagram showing the spectral reflectance of g-35%Zn-3,5%Cd alloy foil, Figure 5 shows the change over time of Ag-35Zn binary alloy and Ag-35Zn-3゜5Cd alloy. FIG. 3 is a diagram showing the accompanying change in spectral reflectance difference.

Claims (1)

[Claims] 1. Silver as the main component, 30 to 46% zinc and 10% or less cadmium by weight; 1A, 2A, 4A, 5A, 6A, 7
A variable spectral reflectance alloy comprising an alloy containing a total of 15% by weight or less of one or more of Group A, 8, 1B, 3B, 4B, 5B, and rare earth elements. 2. A part of the alloy surface having a different crystal structure at a first temperature higher than room temperature and a second temperature lower than the first temperature in the solid state is formed by rapid cooling from the first temperature. having a crystal structure different from the crystal structure at the second temperature,
2. The variable spectral reflectance alloy according to claim 1, wherein the other alloy has a crystal structure at the second temperature and has a spectral reflectance different from that of the rapidly cooled crystal structure. 3. The variable spectral reflectance alloy according to claim 1 or 2, wherein the alloy contains an intermetallic compound. 4. The spectral reflectance modified alloy according to any one of claims 1 to 3, wherein the first temperature is higher than a solid phase transformation point. 5. The difference between the spectral reflectance of the material having a crystal structure formed by the rapid cooling and the spectral reflectance of the material having the crystal structure at the low temperature formed by non-quenching is 5% or more. Claims 1 to 4, which are
The variable spectral reflectance alloy according to any one of paragraphs. 6. Claims 1 to 5, characterized in that the spectral reflectance of the alloy is 10% or more at a wavelength of 400 to 1000 nm.
The variable spectral reflectance alloy according to any one of paragraphs. 7. The variable spectral reflectance alloy according to any one of claims 1 to 6, wherein the alloy is a non-bulk material. 8. The variable spectral reflectance alloy according to any one of claims 1 to 7, wherein the alloy has a crystal grain size of 0.1 μm or less. 9. The variable spectral reflection alloy according to any one of claims 1 to 8, wherein the alloy is any one of a thin film, foil, strip, powder, and thin wire. 10, mainly composed of silver, 30 to 46% zinc and 10% or less cadmium by weight, 1A, 2A, 4A, 5A, 6A,
A recording material comprising an alloy containing a total of 15% by weight or less of one or more of groups 7A, 8, 1B, 2B, 3B, 4B, 5B, and rare earth elements. 11. An alloy having different crystal structures in a solid state at a first temperature higher than room temperature and a second temperature lower than the first temperature, wherein at least a part of the alloy surface is at the first temperature. 11. The recording material according to claim 10, wherein the recording material has an alloy composition that forms a crystal structure different from the crystal structure at the second temperature when quenched from the temperature. 12. The foil or thin wire formed by pouring the molten metal of the alloy onto the circumferential surface of a rotating roll made of a highly thermally conductive member, according to claim 10 or 11. Recording materials. 13. The recording material according to claim 10 or 11, which is a thin film formed by depositing the alloy by vapor deposition or sputtering. 14. The recording material according to claim 10 or 11, which is a powder obtained by spraying the molten metal of the alloy using a liquid or gas cooling medium.