JPH0436097B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel germanium-molybdenum based amorphous compound material and a method for producing the same. In recent years, with the development of electronics and related technologies, research has been actively conducted on oxide-based ceramics, mainly germanium oxide (GeO ₂ ), and their single crystals.
Research is being conducted as a conversion element material in fields such as atmospheric gas-electricity, photoacoustic polarization, and X-ray spectroscopy, and as a catalyst material. As a stable compound of GeO ₂ and MoO ₃ , there are several types of crystals.
Although research on single crystallization has been actively conducted, research on amorphous compounds has not been conducted. The present invention provides a germanium-molybdenum-based amorphous oxide, which has been completely unknown heretofore. That is, the present invention provides a novel germanium-molybdenum-based amorphous compound material having the composition (GeO ₂ ) _1-X (MoO ₃ ) _X (where 0<x≦0.50), and (GeO ₂ ) _{1- X}・( _MoO3 )
This relates to a method for producing a germanium-molybdenum amorphous compound material, which is characterized by heating and melting a mixture of germanium oxide and molybdenum oxide corresponding to _X (where x is the same as above) and then ultra-quenching the mixture. be. The germanium-molybdenum-based amorphous oxide of the present invention can be used for photoresponsive devices, temperature-responsive devices, optical memory materials, ion conductive materials, optical recording tapes, catalysts,
It is useful as a light-transmitting conductive material, a dielectric material, a photo-electrical switching device, a thermo-electrical switching device, etc. In the present invention, the term "germanium-molybdenum amorphous compound" includes not only an amorphous compound but also a compound containing a polycrystalline phase in the amorphous compound. The germanium-molybdenum amorphous oxide of the present invention is produced as follows. The raw material used in the present invention is a mixture of germanium oxide and molybdenum oxide, and its composition ratio is (GeO ₂ ) _1-X・(MoO ₃ ) _X (0<x≦
0.50). A raw material mixture having the above composition ratio is heated and melted, and then cooled extremely rapidly. The heating and melting may be carried out at a temperature higher than the temperature at which these raw material mixtures are sufficiently melted, preferably at a temperature of 50 to 50°C higher than the melting temperature.
Temperature range as high as 200℃, especially preferably 80~150℃
Heat at a moderately high temperature. There are no particular restrictions on the atmosphere during heating, and heating is usually performed in air. Next, the melt of the raw material mixture is ultra-quenched. Ultra-quenching is an essential requirement for the method of the present invention, and only through this can a new amorphous compound be obtained. Ultra-rapid cooling is usually performed at a cooling rate of about 10 ⁴ to ^{10 6} °C/sec.
This ultra-rapid cooling can be carried out by a wide variety of methods as long as it can be cooled at the above-mentioned cooling rate.The melt of the raw material mixture is injected onto the surface of a roll rotating at high speed and solidified in the atomic arrangement of the liquid state. A typical example is the method of forcing people to do something. An example of a quenching apparatus for a molten raw material mixture used in carrying out the method of the present invention will be described below with reference to the drawings. FIG. 1 shows a front view of the rapid cooling device main body 3 installed on the pedestal 1. As shown in FIG. The quenching device includes dielectric heating coils 5, 5..., a tube 7 for heating the raw material, a support 9 for the tube 7, a nozzle 11 for spouting the molten raw material,
Rapid cooling roll 13, cooling nozzle 1 of nozzle 11
5, the main components include an overflow prevention air nozzle 17, a fine adjustment mechanism 19 for the nozzle 11, an air cylinder 21, a receiving box 23 for the cooled material, a cooled material outlet 25, etc. By installing a fan for cooling the roll inside the cooling roll 13 and providing an air blowing port at the end of the roll surface, the molten raw material can be rapidly cooled stably. FIG. 2 shows details of the support 9. In FIG.
9. A cooling water discharge path 31, a blow air introduction furnace 35 equipped with a needle valve 33, a mechanism 37 for finely adjusting the distance between the surface of the roll 13 and the nozzle 11, and a rectifying perforated plate 39 for uniformly extruding the raw material melt. We are prepared. When carrying out the method of the present invention using the quenching device 3 shown in FIGS. 1 and 2, a raw material mixture of a predetermined composition is first stored in a tube 7 having a nozzle 11 for blowing out the melt. The tube 7 is preferably made of a material that is sufficiently durable under high-temperature oxidizing atmosphere conditions, such as platinum, platinum-rhodium, iridium, silicon nitride, boron nitride, or the like. Note that the material of the portion not in direct contact with the raw material melt may be high melting point ceramics, glass, or metal. The shape of the nozzle opening is appropriately determined depending on the target product; for example, a round shape is used for a thin linear material, and a slit-like shape is used for a wide product. The shape of the nozzle opening may be oval or other shape. The raw material mixture stored in the tube 7 is then heated to a temperature equal to or higher than its melting point to form a melt, and then is poured from the mouth of the nozzle 11 onto the surface of the roll 13 rotating at high speed under constant gas pressure. It is blown out and rapidly cooled on the roll surface. The blowing angle of the raw material melt between the nozzle opening and the roll surface may be perpendicular to the roll surface if the width of the target compound is approximately 3 mm or less;
If it is larger than mm, the angle is 0° to 45° with respect to the normal to the roll surface. Although these blowout angle adjustment mechanisms can be incorporated into the device itself as a mechanism that can set a predetermined angle, it is preferable to process the nozzle itself. The heating method for the raw material mixture is not particularly limited, but it is usually carried out in a furnace equipped with a heating element, a dielectric heating furnace, or a condensing heating furnace. The temperature of the raw material melt is preferably 50 to 200°C, preferably 80 to 150°C higher than its melting point. At this time, if it is too close to the melting point,
While the melt is being blown onto the roll surface, there is a risk that it will cool and solidify in the vicinity of the nozzle, and conversely, if the temperature becomes too high, it tends to be difficult to rapidly cool the melt on the roll surface. The heating gas used to blow the melt onto the roll surface is preferably an inert gas, such as argon, nitrogen, helium, etc., but in order to maintain the melt raw material in an oxidized state, dry compression is recommended. Air is preferred. The gas pressure depends on the size of the nozzle opening, but is usually 0.1 to 2.0 Kg/ ^cm2 , preferably 0.5 to 1.0.
It is about Kg/ ^cm2 . Further, the distance between the nozzle opening and the roll surface when blowing out the raw material melt is preferably about 0.01 to 1.0 mm, more preferably about 0.05 to 0.5 mm. If smaller than 0.01mm, the paddle amount will be very small and you will not get uniform material, while 1.0mm
If it is larger than , the amount of paddle may be excessive,
Furthermore, if the thickness is greater than the thickness of the puddle formed by the interfacial tension of the composition melt, there may be a tendency for the puddle to be difficult to form. The material of the roll includes copper and its alloy with good thermal conductivity, the above-mentioned materials having a hard chrome plating layer, copper, stainless steel, and the like. The circumferential speed of the roll is 5 m/sec to 35 m/sec, preferably 10 m/sec.
The target amorphous compound material of high quality can be obtained by rapidly cooling the raw material melt at a speed of 20 m/sec to 20 m/sec. In this case, if the peripheral speed of the roll is 5 m/sec or less, it is not very preferable because it tends to be difficult to become amorphous. When the peripheral speed of the roll is greater than 35 m/s, the shape of the target material obtained becomes extremely thin, and all of it becomes scaly or fine powder-like.
In terms of material structure, it is still an amorphous compound material of the present invention. When producing the compound of the present invention under reduced pressure or high vacuum or in an inert gas atmosphere as the atmosphere in which the melt raw material is blown onto the rotating roll surface, reduction of the raw material melt at high temperature occurs, Oxygen atoms in the composition atoms decrease, and the resulting material becomes colored purple or black. However, this colored product is also a compound of the present invention physically and can be used in a colored state. When heating and melting the raw material mixture in a tube, it is necessary to completely melt the mixture. However, before the mixture is completely molten, some of the molten material may flow out from the nozzle tip, so the nozzle tip is locally cooled to prevent the melt from flowing out. It is preferable to do so. A typical means for locally cooling the nozzle is to blow a cooling gas onto the tip of the nozzle, and the gas may be an inert gas such as argon, helium, nitrogen, etc., but dry, cold compressed air is more preferable. The novel amorphous compound material according to the present invention usually has a thickness of about 50 to 10 μm and is a very brittle material. For this reason, after the material is rapidly cooled and solidified on the roll surface, it is preferable that stress is not applied to the material as much as possible. One of the causes of stress addition is the large turbulent flow in the air layer on the roll surface caused by the wind phenomenon caused by roll rotation in the atmosphere. In order to prevent this turbulence and to improve the adhesion between the molten raw material mixture to be rapidly cooled and the roll surface, a countercurrent blowout nozzle for preventing wind blowing, that is, an air nozzle 17 for preventing excessive flow shown in FIG. 1 is installed. Or, install a fan fixedly inside the roll. In the latter case, the turbulent flow generated inside the roll due to rotation of the roll is absorbed into the roll through a variable-diameter air inlet provided at the end of the roll surface, and is discharged from the front of the roll axis, allowing air to flow over the roll surface. By moving the melt into the interior, the molten material is pressed more tightly against the roll surface, and the roll itself can also be cooled by air blowing and movement. Further, in order to maintain the dimensional uniformity of the obtained material, if grooves for cutting the material are provided on the roll surface at right angles to the rotation direction, the material can be cut to a constant size. The germanium-molybdenum compound of the present invention has an atomic arrangement structure that changes greatly depending on the mixing ratio of raw materials, and can be broadly classified into the following types. First, in the case of 0<x≦0.40, a 100% amorphous compound is obtained, and in the range of 0.40<x≦0.50, an oriented polycrystalline mixed amorphous compound containing a MoO ₃ crystal phase is obtained, When 0.50<x, a material mainly composed of MoO ₃ crystal phase can be obtained. FIG. 3 shows the production range of the material of the present invention. The peripheral speed of the quenching roll of the quenching device used is
Within the range of 5 m/sec to 35 m/sec, no major changes are observed in the structure of the material obtained in each composition range. In addition, (GeO ₂ ) _1- obtained as described above
After subjecting a _germanium -molybdenum based amorphous compound material having a composition of _X・(MoO ₃ )
By heat-treating the compound material at a temperature below the crystallization temperature for a predetermined period of time, an oriented polycrystalline thin film material can be obtained. The oriented polycrystalline thin film material obtained in this way can be used for optical memory materials, optical-thermal memory materials, optical waveguide devices, optical mirrors, surface wave devices, photoacoustic devices, piezoelectric transducers, pyroelectric devices, and photoelectric devices. It is useful as a transparent electrode material, bypass capacitor, optical switch, electromic device, light modulation device, humidity sensor, temperature sensor, chemical sensor, catalyst, etc.
Note that even at temperatures below the crystallization temperature, if the heat treatment time is too long, a non-oriented polycrystalline material will result, so care must be taken in this regard. For example, in (GeO ₂ ) _1-X・(MoO ₃ ) _X , x=
The crystallization temperature of the germanium-molybdenum amorphous compound material 0.25 is 745°C, and when this is heat-treated in the air, the following materials can be obtained depending on the conditions. 1 740℃×10 minutes: Oriented polycrystalline material 2 740℃×30 minutes: Polycrystalline material 3 670℃×10 minutes: Amorphous material 4 670℃×30 minutes: Oriented polycrystalline material 5 670℃×60 Min: Polycrystalline When identifying the structure of the material of the present invention, the presence or absence of crystallinity was confirmed and structural analysis was performed using X-ray diffraction and a polarizing microscope, and a very small portion was observed using a scanning electron microscope. The features of the present invention will be further clarified by examples below. Example 1 GeO ₂ (purity 99.9%) and MoO ₃ (purity 99.9%) were blended in a predetermined composition, mixed uniformly, and heated to 850°C.
The mixture was calcined for 30 minutes and used as a raw material for a composition. The obtained composition raw material was made into a platinum tube (diameter 10 mm x length 150 mm).
and installed in the dielectric heating coil, oscillating tube fiber voltage 13V, anode voltage 10KV, grid current 120~
Dielectric heating was performed under the conditions of 150 mA and anode current of 1.2 to 1.8 A. The completely molten raw material was blown out onto the surface of a rotating rapid cooling roll using dry compressed air to rapidly cool it. Tables 1 and 2 show the composition and manufacturing conditions. Samples Nos. 1 to 20, 25 and 29 in Tables 1 and 2 show ribbon-shaped amorphous oxide materials of the present invention. In addition, No. 24 is a thin piece due to the high roll rotation speed, but it can be used in fields such as catalysts where there are no restrictions on shape. Note that nozzle shape A indicates a slit-like nozzle of 0.2 mm x 4 mm, and nozzle shape B indicates a circular nozzle with a diameter of 0.2 mm.

【table】

【table】

【table】

[Table] Reference Example 1 (GeO ₂ ) _1-X・( _{MoO 3} ) Samples Nos. 8, 10, 12, 13 and
The X-ray diffraction results for 15 are shown in FIG. The peripheral speed of the quenching roll starts from 5.18m/sec (No.8)
It is clear that there is no significant change in the atomic arrangement structure of the material obtained within the range of 34.54 m/sec (No. 15). Reference Example 2 FIG. 5 shows the results of differential thermal analysis of Sample No. 7 of Example 1, which corresponds to x=0.25 in (GeO ₂ ) _1-X ·(MoO ₃ ) _X . In FIG. 5, Tc represents the crystallization temperature, Tg represents the glass transition point, and mp represents the melting point. Reference Example 3 A photograph showing the appearance of sample No. 7 of Example 1, which corresponds to x=0.25 in (GeO ₂ ) _1-X ·(MoO ₃ ) _X , is shown as a reference drawing. Reference Example 4 Scanning electron micrographs (20,000x and 620x) of sample No. 9 of Example 1 are shown as reference drawings and 620x, respectively. Reference Example 5 FIG. 6 shows the infrared absorption spectrum of sample No. 13 of Example 1, which corresponds to x=0.33 in (GeO ₂ ) _1-X ·(MoO ₃ ) _X . Example 2 When sample No. 17 of Example 1 was heat-treated in air at 670°C for 30 minutes and then subjected to X-ray diffraction, it showed one sharp diffraction peak at the diffraction angle (2θ), indicating that it was amorphous. A change from the structure to an oriented polycrystalline structure was confirmed.

[Brief explanation of drawings]

FIG. 1 is a front view of an example of a quenching device for melted raw materials used in the method of the present invention, and FIG.
FIG. 3 is a diagram showing the composition range of the material of the present invention; FIG. 4 is an X-ray diffraction diagram of some of the material of the present invention; FIG. 5 is a diagram showing the composition of the material of the present invention. FIG. 6 shows the infrared absorption spectrum of another material according to the present invention. 1... Frame, 3... Rapid cooling device main body, 5, 5...
Dielectric heating coil, 7... raw material heating tube,
9... Support for raw material heating tube, 11... Nozzle for spouting molten raw material, 13... Roll for rapid cooling, 1
5... Cooling nozzle for nozzle 11, 17... Excess flow prevention air nozzle, 19... Fine adjustment mechanism for nozzle 11, 21... Air cylinder, 23... Receiving box for cooled material, 25... Cooling material Outlet, 2
7... Valve, 29... Cooling water introduction path, 31...
Cooling water discharge path, 33... Needle valve, 35...
...Blow air introduction path, 37... Mechanism for finely adjusting the distance between the roll 13 and the nozzle 11, 39... Perforated plate for rectification.

Claims (1)

[Claims] 1 (GeO ₂ ) _1-X・(MoO ₃ ) _X (0<x≦0.50)
A germanium-molybdenum amorphous compound material having the following composition. 2. The germanium-molybdenum based amorphous compound material according to claim 1, wherein 0<x≦0.40. 3. The germanium-molybdenum based amorphous compound material according to claim 1, wherein 0.40<x≦0.50. 4 A mixture of germanium oxide and molybdenum oxide is heated and melted, and then the melt is ultra-quenched (GeO ₂ ) _1-X (MoO ₃ ) _X (where 0<x
≦0.50) A method for producing a germanium-molybdenum based amorphous compound material. 5. The method for producing a germanium-molybdenum based amorphous compound material according to claim 4, wherein the material is ultra-quenched at a cooling rate of 5 10 ⁴ to 10 ⁶ °C/sec. 6. The method for producing a germanium-molybdenum amorphous compound material according to claim 4 or 5, wherein the raw material melt is ultra-quenched by contacting it with a solid. 7. Pour the raw material mixture into a heating tube equipped with a nozzle with a slit-shaped, circular or oval outlet, heat and melt at a temperature 50 to 200°C higher than the melting point of the mixture, and then heat for 5 to 35 m. The germanium-molybdenum amorphous compound according to any one of claims 4 to 6, wherein the melt is blown out through the nozzle onto the surface of a roll rotating at a circumferential speed of 1/2 to ultra-quench it. Method of manufacturing materials.