JPH0328377B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel bismuth-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 bismuth oxide (Bi ₂ O ₃ ), 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 Bi ₂ O ₃ and MoO ₃ , only a few types of crystals have been described in a few documents, and although research on the single crystallization of these compounds is being actively conducted, , no studies have been conducted on amorphous compounds. The present invention is based on bismuth, which was completely unknown in the past.
The present invention provides a molybdenum-based amorphous oxide. That is, the present invention provides (Bi ₂ O ₃ ) _1-X・( _{MoO 3} )
(However, 0.55≦x≦0.95) A new bismuth-molybdenum based amorphous compound material, and (Bi ₂ O ₃ ) _1-X・(MoO ₃ ) _X (where x is the same as above)
A bismuth ^- molybdenum based amorphous compound material characterized by heating and melting a mixture of ^bismuth oxide and molybdenum oxide corresponding to This relates to the manufacturing method. The bismuth-mirabudene-based amorphous compound material of the present invention can be used for photo-electric response devices, photo-magnetic response devices,
It is useful as a highly ionic conductive material and an oxidation/dehydrogenation catalyst in organic synthesis. Since the bismuth-molybdenum amorphous compound material of the present invention is obtained in the form of a thin film, it can be used as a film as it is, and has particularly excellent transparency for infrared rays of a specific wavelength (near 1100 cm ^-1 ) emitted by humans. This makes it useful as a filter for infrared sensors. The bismuth-molybdenum amorphous oxide of the present invention is produced as follows. The raw material used in the present invention is a mixture of bismuth oxide and molybdenum oxide, and its composition ratio is (MoO ₃ ) _X・(Bi ₂ O ₃ ) _1-X (0.55≦x≦
0.95). 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.
Heating is performed at a temperature higher than 200°C, particularly preferably 80 to 150°C or higher. 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. Super rapid cooling is usually 10 ⁴
The cooling rate is approximately 10 ⁶ °C/sec. A wide variety of methods can be used for this ultra-rapid cooling as long as it can be cooled at the cooling rate mentioned above.The melt of the raw material mixture is sprayed onto the surface of the 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. Figure 1 shows the rapid cooling device main body 3 installed on the stand 1.
shows a front view. The quenching device includes dielectric heating coils 5, 5, .
5, the main components include an air nozzle 17 for preventing swirling, a fine adjustment mechanism 19 for the nozzle 11, an air cylinder 21, a receiving box 23 for the cooled material, a cooling material outlet 25, etc. By installing a fan for cooling the quenching roll 13 inside the quenching roll 13 and providing an air blowing port at the end of the roll surface, the molten raw material can be quenched stably. FIG. 2 shows details of the support 9. In FIG.
9. A cooling water discharge path 31, a blow air introduction path 35 equipped with a needle valve 33, a fine adjustment mechanism 37 for 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 nozzle shape may be oval or other shape. The raw material mixture stored in the tube 7 is then heated to a temperature 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, and perpendicular to the roll surface if the width is approximately 3 mm or more. It is between 0° and 45°.
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 out 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 pressurizing 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 is copper and its alloy with good thermal conductivity, the above-mentioned materials having a hard chrome plating layer, steel, stainless steel, etc. The circumferential speed of the roll is 5 m/sec to 35 m/sec, preferably 10 m/sec to 20 m/sec.
m/sec, and by rapidly cooling the raw material melt, the desired amorphous compound material of good quality can be obtained. In this case, if the peripheral speed of the roll is 5 m/sec or less, it tends to be difficult to become amorphous, which is not very preferable. When the peripheral speed of the roll is higher than 35 m/sec, the shape of the target material obtained becomes extremely thin and becomes scaly or fine powder, but in terms of material structure, it is still the amorphous compound material of the present invention. It is. 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, it is preferable that no stress is applied to the milled material after it is rapidly cooled and solidified on the roll surface. 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 swirling as shown in FIG. 1 is installed. , a fan is fixedly installed 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 atomic arrangement structure of the bismuth-molybdenum compound of the present invention varies greatly depending on the mixing ratio of raw materials, and can be broadly classified into the following types.
First, if 0.55≦x≦0.95, it is an amorphous compound.
In the range of 0.35≦x<0.55, a mixture of a small amount of δ-Bi ₂ O ₃ polycrystalline phase and an amorphous compound is obtained, and in the range of 0<x<0.35, it is obtained as a high ionic conductor. A mixture containing useful δ-Bi ₂ O ₃ is 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 order to identify the structure of the material of the present invention, the presence or absence of crystallinity was confirmed and structurally analyzed 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 Bi ₂ O ₃ (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 21 in Tables 1 and 2 show ribbon-shaped amorphous compound materials of the present invention. Also,
No. 22 is a thin piece due to its large roll rotation speed, but it can be used in fields such as catalysts where there are no restrictions on shape. Note that Nos. 23 to 27 are comparative examples. Note that nozzle shape A indicates a slit-like nozzle with a size of 0.2 mm x 4 mm, and nozzle shape B indicates a circular nozzle with a diameter of 0.2 mm. Also, for example, the composition x=0.90 means (Bi ₂ O ₃ ) _1-X・(MoO ₃ ) In _X , (Bi ₂ O ₃ ) _0.10・
(MoO ₃ ) _0.90 .

【table】

【table】

【table】

[Table] Reference Example 1 (Bi ₂ O ₃ ) _{1-X ・}(MoO ₃ ) Shown in Figure 4. The peripheral speed of the quenching roll changed from 5.18 m/sec (No. 7) to 34.54 m/sec.
It is clear that no major change was observed in the atomic arrangement structure of the material obtained within the range of 1.5 seconds (No. 8). Reference Example 2 FIG. 5 shows the differential thermal analysis results of sample No. 5 of the above example, which corresponds to x=0.70 in (Bi ₂ O ₃ ) _1-X ·(MoO ₃ ) _X . In FIG. 5, Tc indicates the crystallization temperature and Tg indicates the glass transition point. The exothermic peak due to crystallization is 383°C. Reference Example 3 A photograph showing the appearance of sample No. 12 of the above example corresponding to x=0.65 in (Bi ₂ O ₃ ) _1-X ·(MoO ₃ ) _X is shown as a reference drawing. Reference Example 4 A scanning electron micrograph (20,000x magnification) of sample No. 12 of the above example is shown as a reference drawing. Reference Example 5 (Bi ₂ O ₃ ) _{1-X ・}(MoO ₃ ) The spectrum is shown in FIG. As is clear from Table 6, the bismuth-molybdenum amorphous compound material of the present invention exhibits good infrared transmittance at around 1100 cm ^-1 . Reference Example 6 (Bi ₂ O ₃ ) _1-X・(MoO ₃ ) Films prepared for Sample No. 2 of the above example corresponding to x = 0.90 and Sample No. 8 corresponding to x = 0.70 in _X The infrared transmittance was measured as it was. The results are shown in the table below. Wavelength (cm ^-1 ) Transmittance (%) No. 2 No. 8 4000 11 13 3000 13 16 2000 15 17 1500 22 18 1300 40 20 1200 58 32 1100 70 55 1000 35 56 800 3 3 500 5 4 Reference example above As is clear from the results of 5 and 6, the bismuth-molybdenum amorphous compound material of the present invention particularly transmits infrared rays with a wavelength around 1100 cm ^-1 , so it can be used as an infrared sensor used for night security of buildings, etc. It can be used as a filter.

[Brief explanation of the drawing]

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 of the quenching device according to the invention. The differential thermal analysis diagram of one material, FIG. 6, respectively shows the infrared absorption spectrum of the material according to the 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... Eddy current prevention air nozzle, 19... Fine adjustment mechanism for nozzle 11, 21... Air cylinder, 23... Cooled material receiving box, 25... Cooling material take-up exit, 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 (Bi ₂ O ₃ ) _1-X・(MoO ₃ ) _X (0.55≦x≦
A bismuth-molybdenum amorphous compound material having a composition of 0.95). 2. (Bi ₂ O ₃ ) _1- characterized in that after heating and melting a mixture of bismuth oxide and molybdenum oxide, the melt is ultra-quenched at a cooling rate of 10 ⁴ to ^{10 6} °C/sec.
A method for producing a bismuth-molybdenum amorphous compound material having a composition of _X. (MoO ₃ ) _X (0.55≦x≦0.95). 3. Bismuth according to claim 2, in which the raw material melt is ultra-quenched by contacting it with a solid.
A method for producing a molybdenum-based amorphous compound material. 4. The raw material mixture is put into a heating tube equipped with a nozzle equipped with a slit-shaped, circular or oval outlet, and after heating and melting at a temperature 50 to 200°C higher than the melting point of the mixture, the mixture is heated at 5 m/sec. The bismuth-molybdenum-based amorphous compound material according to claim 2 or 3, wherein the melt is blown out through the nozzle onto the surface of a roll rotating at a circumferential speed of ~35 m/sec to ultra-quench it. Manufacturing method.