TW200927641A - Nanosize structures composed of valve metals and valve metal suboxides and process for producing them - Google Patents

Abstract

Novel strip-like or sheet-like valve metal and valve metal oxide structures having a transverse dimension of from 5 to 100 nm are described.

Description

200927641 VI. Description of the invention: [Technical field to which the invention pertains] The method of manufacturing a valve of 100 mm. 5 ❹ 10 15 ❹ 20 The present invention relates to a layered structure having a directional genus and a valve gold oxide: [Prior Art] A microstructure of a metal substrate having a larger surface of a larger metal substrate and a microstructure Forms of metal and media, catalyst carrier materials, thin films and porous applications, such as implant materials in the field of touch medicine, and the technical field of large-scale materials, medical storage materials and The anode characteristics of the capacitor are applied to the two W0 00/67936 to expose the gas phase.

Ca, Li and Ba' reduce the valve metal oxides, as a method of genus, such as bismuth, Ab powder. Due to oxidation = finely dispersed metal, you also become a metal in the process of volume and the volume expansion of the two metals to form a solid oxide, 2 two 2 surface area of highly porous valve metal powder, which is particularly suitable for the manufacture of solid electrolyte Capacitor. It has been found that under special-recovery conditions, a layered structure can be formed with a lateral nanometer scale, and the initial layer comprises alternating metal oxide layers and oxidized reducing metals. Floor. Dissolving and filtering the oxide of the reducing metal in the inorganic acid completely removes the oxide of the reducing metal of the nano-valve metal structure. Depending on the geometry of the starting valve metal oxide, a finely divided powder having a layered structure or strip or 3 200927641 layered surface structure on a metal substrate of a relatively coarse/large size structure having a width a strip or layer of metal and/or metal suboxide of less than 1 〇〇 nm, and its gap (interlayer distance) up to twice the strip width, depending on the valve metal oxide and its oxidized state . 5 SUMMARY OF THE INVENTION Therefore, the use of a finely dispersed valve metal oxide having an average particle diameter of a basic structure of 5 to 2 Å, preferably less than 500 mn, more preferably less than 3 Å, is used. When the powder is obtained, a finely dispersed metal or a ruthenium-underoxide powder having a layered structure and a metal or suboxide strip having a width of 5 to 1 〇〇 nm, preferably 8 may be obtained. Up to 50 nm, especially, at most 3 〇 nm; and its lateral dimension is 4 〇 to 5 〇〇 11111, and the specific volume is higher than 20 m 2 /g ' preferably higher than 50 m 2 /g. When a relatively large metal 15 & substrate having a scale exceeding, for example 10 μηη′, is used, a metal or suboxide strip having a width of at most 100 nm, preferably 5 to 80 nm, is obtained. It is particularly preferably 8 to 5 5 nm, more preferably up to 3 G fine, and the gap is a structure of the strip width - to twice the structure. The depth of the groove between the strips is at most 丨. Larger metal structures or substrates, such as wires or foils, can be obtained by first chemically or anodically oxidizing the surface, and then reducing the surface according to the present invention to obtain a strip-like structure with a strip depth. Determined by the thickness of the oxide layer. Further, the structure according to the present invention can be obtained by providing a substrate comprising, for example, other gold 4 200927641 genus or ceramics having a (4) metal oxide, such as by application. By vapor deposition or electro-coating, the coating can be oxidized and returned to the shoulder according to the invention. Chemical or secondary oxygen 5 ❹ 10 15 ❹ 20 Valves used in accordance with the purpose of the present invention are fully disclosed.

Ta, Mo, W and Hf, and alloys thereof (mixed oxides 1 and ^V, Nb, Zf, Nb and Ta are preferred, especially Nb and τ, with Tl,

Nb〇2 and Ta2〇5 are particularly preferred starting oxides, Nb2〇5, and the resulting product is preferably a metal of the starting oxide: = household: lower oxygen (tetra) oxide ( :Oxide) can also be specially selected to have a special preference, the wire has a metal oxide, the chemical formula is Nb0x, the basin is o?n, the sharp_time_ and the surface (Ta), and also the u 'except metal sharp A particularly preferred range is up to 5 V, more preferably to a reducing metal, in which m' can be alloyed. The preferred material may be ton, & bis, B = j original gold; | oxime oxide active _, M # A1 co-dissolved alloy is preferred. Specially, it is characterized by the doping of 500ppm in the content of the reducing metal. The reason is that the reduction process 〇〇-^==^\ scale structure method 'basically and wo field Similarly, the metal 5 200927641 oxide is reduced by a reducing metal in the form of a vapor. Here, the valve metal oxide to be reduced to a powder form is contacted with a reducing metal vapor in the reactor. The reducing metal is volatilized and propagated by the action of the carrier gas stream, such as generally at 900 to 1200 ° C under the same dish, with argon gas passing through the valve metal oxide 5 powder on the wire or in the steel, The general temperature holding time is from 30 minutes to several hours. Since the valve metal oxide has a molar volume of about two to three times that of its corresponding valve metal, there is a considerable reduction in volume during the reduction process. In the reduction procedure, a highly porous sponge-like structure in which an oxide of a bismuth metal is deposited is formed. Since the molar volume of the oxide of the reducing metal is higher than the volume of the metal oxide of the valve metal oxide and the valve gold, the residual stress is generated when it is mixed into the pores. The oxide of the reducing metal in the structure can be removed from the structure by dissolving it, and a highly porous metal powder can be obtained. The reduction reaction mechanism, the formation and distribution of pores are described as follows: from the metal oxide particles of the reduction valve or the small reaction nuclei on the surface of the substrate, a layered structure with a scale of 15 nm is used in the valve metal/阙Formed after the reaction shovel in the initial reaction phase of the metal oxide, the layers are initially oriented perpendicular to the surface of the particle/substrate region on the near surface, however, when the reaction front moves toward the oxide particles/substrate In the deep part, the direction and dimension of the layer are determined by the crystal orientation and scale of the main particles in the valve metal oxide and the reaction conditions. A certain number of lattice planes in the oxide metal grains of the valve gold are replaced by a chemically equivalent number of valve crystals of the metal and the oxide of the reducing metal. These nano-sized layered structures, which are actually very strongly unfavorable due to their high interfacial stress, can still be prepared and become feasible due to the reduction of the intense exothermic reaction and at least part of the excess energy not in the form of heat. Dissipated, but "input, to 6 200927641 5

10 15 ❹ , "Formation of the structure" makes it a fast reaction power. The flat interface can be used as a reducing metal in the original day. Many of them allow quick money, so in the case of its creation, the total reaction system is reduced. Energy. However, the layered structure containing the distant and effective oxides only forms a low-energy structural state after the metamorphic gold, and then forms a salty lower energy structure. The heat treatment time and the fixed reaction are long. Conditions (such as temperature is 2, relative vapor pressure r is normal, implementation, 1 纴逷 original metal is too large to avoid the occurrence of the rule, change the order, Nai water size layer 1 纟 #_ change the coarse and mutual The area of the valve containing the gold f region and the _ metal oxide structure's package has found that 'before the structural transformation, if the object cools down to a certain warm sound, the beer is reduced to the pupa (four) The layered structure of the zirconia is stable, and the layered structure can be cooled; east. According to the invention, the reducing condition can be sure that the reduction can be carried out uniformly in a short time. In other words, if used Starting oxide, t reduction procedure is completed After that, it is cooled as quickly as possible in the powder bed of the oxide and the substance. For this reason, it is preferable to use a powder bed of a lower thickness to ensure that the vapor of the reducing metal can be infiltrated into the powder. In the bed, the thickness of the powder bed is preferably less than 1 cm, especially less than 0.5 cm. Person 20 In addition, the reducing metal vapor can be uniformly ensured by providing a long free path length of the reducing metal vapor. In the infiltrated powder bed, according to the present invention, the reduction reaction is therefore more suitable for carrying out at a low pressure, more preferably under the condition of no carrier gas. The reduction reaction is particularly suitable for the vapor pressure of the reducing metal vapor in an oxygen-free environment. 1〇-2 to 〇·4 bar, more suitable for 〇7 200927641 Good for less than cut Low carrier gas pressure for at most G.2bar, more) Pure gas: such as gas and atmosphere? When the type of carrier gas can be fined, the rate of increase of the structure is reduced as the depth is increased, and the reduced metal layer is formed between the metal layer and the metal layer.

10 15

The diffusion path of the current interface grows. A change has been made. ...when the original degree is up to 1 μΠ1, the substantially non-layered structure of the valve metal oxide powder according to the invention has a minimum cross-sectional dimension of the main structural particle size (grain size) of preferably not more than 2 Calling, not exceeding 1 is better, and the average is not more than 〇5. If the main structure of the valve metal oxide powder has a relatively small particle size, it can be used for the porous sintered agglomerate. It is beneficial to the main particles that want to be strongly sintered together, but the class structure network of the open pores exists between the main particles of the aggregation, so the pore size distribution of the open pores can directly reach the vapor of the reducing metal and restore a large part. The main particle surface. Although the effect is significantly smaller than that of the pores, the grain boundaries between adjacent major particles can accelerate diffusion. Therefore, in addition to the small primary particles and the open porosity, a high proportion of grain boundaries between the main particles to be formed in the aggregated valve metal oxide particles is favored. The above can be formed by the optimization of the particle size of the main particles and the sintering of the hydroxide precursor with the hydroxide precursor to form a valve metal oxide. The temperature at which the simmering is carried out is preferably 4 to 700 ° C, particularly preferably 500 to 600 ° C. In the preparation of the metal foil and the wire having the layered surface structure, it is preferable that the metal foil or the wire surface used has a thickness of less than 丨μπι, more preferably less than 0.5 μm. After the reduction reaction at a low pressure, the progress time may be from several minutes to several hours, preferably from U) to 9G minutes, depending on the use of the metal vapor or metal vapor mixture and its vapor pressure, and the reduction reaction is stopped. Can be interrupted by the supply of reducing metal vapor, and idle cooling of the reduced flash metal to a temperature less than loot: 'to stabilize the valve metal or valve metal suboxide ^ and the nanostructure of the reducing metal oxide, different directions The adjacent reed structure is sintered and forms an acceptable slightly larger size. The cooling procedure, 10 is carried out by introducing a protective gas (cooling gas) such as argon and 氦i for: fast pressurization. A more appropriate procedure is to cool A to 300 °C in 3 minutes, then cool to 2 另一个 in another 3 minutes, and cool to 1 °C in another minute. According to the present invention, the reduction procedure is preferably carried out at a lower temperature, and the purpose of the reduction is to reduce the size of the nanolayer structure. The valve metal gas reduction temperature is from 500 to 850 ° C, preferably less than 750 V, and that it is preferably less than 650 ° C. Here, the actual temperature should exceed the initial temperature of the reduction reaction because the reduction reaction is an exothermic reaction. In the present invention, in order to avoid the nano-layered structure, integrity or size increase of the reaction product and the redox gold 20-based oxide which is formed at the beginning of the reduction reaction, different measurement methods may be selected or Is the binding side = for example, at a high reduction temperature, by providing an efficient and rapid collection of reducing metal vaporization, a short reduction time can be sufficiently ensured, for example, a small starting metal oxide powder bed and/or a low The carrier gas pressure, two • Lu Lu 9 200927641 The force: its atomic free path of reducing metal vapor. time. At the low reduction temperature, the surface can be subjected to a longer reduction. It requires less stringent structure 2: the valve metal oxide agglomerate, after the reduction reaction has been completed. Purify by introducing oxygen or air ===Stepwise Ο 10 15 ❹ If it is aged, such as by means of inorganic acid, such as hydrochloric acid or a mixture thereof, then rinse with deionized water until neutral, In the example of the finely divided powder, it is composed of a main type having a flat shape, and the structure of the structure of the 'Tianxian County (10) is long into other structures. After the removal of the cardiogenic metal oxide crane, the independent wide metal layered junction is still stable in the quasi-metallic structure, because it is fully burned with the adjacent layer, (7) 'usually borrowing the tail of the vertical layer _ In the layered structure in the same direction, the original (polycrystalline) valve metal oxide particles are thus converted into aggregated valve metal particles whose main particles contain layered structural groups in different directions, and which are sintered to each other. In summary, a stable, interpenetrating metal structure and a "flat" hole are thus formed. [Embodiment] FIG. 1 is a view showing an apparatus for carrying out the procedure of the present invention, which broadly denotes a reactor having a reduction chamber 2. Reference numeral 3 denotes a temperature controller including a heating coil and a cooling coil. Protection or filling of gas or cold 20 200927641 However, the gas is introduced into the reduction reaction chamber by a valve, and its introduction direction is arrow 4. The direction in which the reduction reaction chamber is evacuated or the gas is removed is arrow 5. The reduction chamber 2 is joined to the gasification chamber 6 of the reducing metal and additionally provides a separate heating source 7. The gasification chamber and the reduction chamber are thermally insulated by the valve region 8 for 5 〇 10 15 20 . The valve metal oxide is reduced in the boat 10 in the form of a thin powder bed. If a valve metal oxide foil or wire or a foil or wire having a valve metal oxide surface is used, it is preferred to hang vertically and parallel to the flow direction of the reducing metal vapor in the reduction chamber. The reducing metal in the boat 9 is heated to a temperature which provides the desired vapor pressure. In the hull, the oxide powder was introduced into a powder bed having a height of 5 mm, and a boat-shaped body containing magnesium chips was placed in a gasification chamber, and the reactor was filled with argon gas. The reduction chamber is then heated to the reduction temperature and the pressure is evacuated to 〇1 bar. The gasification chamber is then heated to 8 Torr. 〇, at this time the lock vapor pressure (static) is about 0.04 bar. After 30 minutes, the heating source of the reduction chamber and the gasification chamber was turned off, and the argon gas cooled down from the 200 bar was introduced into the reduction chamber for another period of time 'at the same time, the chamber wall of the reduction chamber was water. Cool it down. Figures 2, 3 and 4 are transmission electron microscope images at different magnifications after preparation of the reaction product by ion beam focusing in accordance with the present invention. The dark strip in the figure is the layer of the button, and the lighter strip = the layer of magnesium oxide. The layer structure in different directions corresponds to the crystal orientation of the starting pentoxide button. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating a device for carrying out the procedure of the present invention, 11 200927641 FIG. 2 is a transmission electron microscope of a reduced macro powder prepared by ion beam focusing in accordance with the present invention. image. Fig. 3 is a diagram showing the penetration of a giant powder according to the present invention after preparation of a reaction product by ion beam focusing. The anti-living invention _ peak is prepared by ion beam focusing to prepare the reaction product slave penetrating money _ micro-mirror image.

10

[Main component symbol description] 1 reactor 2 ring original chamber 3 temperature controller 6 gasification chamber 7 heating source 8 valve area 9 boat body 10 boat body

Claims (1)

200927641 5 Ο 10 15 ❹ 20 VII. Patent application scope: 1. The valve metal of the shape or sheet is sub-oxidized with the valve metal. The lateral dimension is 5 to 100 nm. It has a 2. = profitable range! The main metal of the bismuth metal and the valve metal substructure ~, having a sheet-like or layered powder bundle, and . 3. According to the scope of the patent application, the metal and sheet metal = oxidized structure, which is in the form of a surface strip structure. Human oxide junction 4. The valve metal structure of the third aspect of the patent scope is a box or a strip having a width of 5 to 1 〇〇 nm and a gap of the type of recognition. (4) (4) to twice the strip width. According to the application of the patent _ i to 4, the valve oxide structure, wherein the strips or sheets are arranged in parallel in the group, 6. = patent application scope ii A valve metal and human oxide structure of any of the five items wherein the lateral dimension or strip width is 8 to 50 nm ' 7. The broad metal structure of any of items 1 to 6 is packaged 3 Zr > V s Nb , Xa % M〇^ w or Ta or an alloy thereof. UAI, in particular Nb 8. According to any of the structures of claims 1 to 6, it has the chemical formula χ), wherein... the secondary oxide 9. According to the scope of the patent application! Up to 8 of the sub-oxide structures are characterized by at least one gold-two, =, to 500 ppm. The method of reducing the metal oxide of the valve is only a method of reducing the metal oxide of the valve, and forming a metal oxide which is sufficient for the reduction of the anti-shore, the production of the original metal vapor, and the formation of the f. The layered na[iota] structure, its special 5 13 200927641 === compound is thermally decomposed and transformed into a layer structure of UK2 to 0.4bar. (4) 12. According to the method of f, the method of claim 1G or n, which is characterized by reduction The ίο product is cooled to less than 1 〇〇 . in a few minutes after the reduction process is completed. The method according to any one of claims 1 to 12, characterized in that Li, bismuth Mg and/or Ca, particularly Mg, are used as the reducing metal. 14. The method according to any one of claims 1 to 13, which is characterized by Al, Hf, Ti, Zr, V, Nb, Ta, Mo and/or w and mixed oxides thereof, in particular Nb Or Ta, as the reduced oxide.