JPH10218689A - Metal doping on inorganic solid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for injecting wanted cations (of a metal) into the inside of an inorganic solid material or controlling a metal component for substituting other metal in the inside of the inorganic solid material. SOLUTION: This method for metal doping on an inorganic solid material is to form a sandwich electrolysis system by adhering one side of an inorganic solid material A to be brought to an object for doping with a solid electrolyte material B containing metal ions (M<n+> ) to be brought for doping and the outside of the solid electrolyte material B to a cathode (plate) C, while adhering the other side of the doping-objective inorganic solid material A to a solid electrolyte material containing arbitrary metal ions or a solid electrolyte material F which is an oxygen ion conductor, and electrically injecting metal ions (M<n+> ) included in the solid electrolyte material on the cathode side into the doping objective inorganic solid material by applying an electric current between the both electrodes. This method is applicable to the fields of various functional materials such as electric and electronic materials, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a metal component in an inorganic solid material, and more particularly to a novel method for doping a metal in an inorganic solid material with a solid electrolyte to impart new properties and functions to the inorganic solid material. Things.

[0002]

2. Description of the Related Art It is known that when various metal elements are added to an inorganic solid material such as ceramics, properties and functions are changed. As a conventional general method for producing such functional ceramics and the like, it has been general to sinter a mixture obtained by mixing raw material powders containing various metal elements at a high temperature of 1000 ° C. or more. However, in such a method, once the ingredients are baked and hardened, the components cannot be changed, and in order to make a difference in the function due to a change in the composition components, it was necessary to adjust at the first stage of mixing the raw materials. As a method of directly injecting metal ions into ceramics, a sputtering method in which metal particles are blasted at high speed and injected is also being attempted, but such a sputtering method only allows metal ions to be introduced near the surface of the material. There were drawbacks.

As for electrochemical doping,
An oxygen ion doping method in which a copper composite oxide ceramic is electrochemically oxidized in an aqueous solution and oxygen ions are injected into the oxide (for example, JCBennet, M. Olfert, GAScholtz
and FWBoswell's reference (Phys. Rev. B, 44, 2727 (1991))
And doping method of electrochemically implanting Li ⁺ ions in non-aqueous solution into oxide ceramics (eg, AMAnd
ersson, CGGranqvistand ZGIvanov literature (J. Alloy
s and Compounds 195,343 (1993)). There is also a method of doping a glass substrate in a molten salt (for example, JP-A-63-79738).

However, all of these methods use a liquid electrolyte, so that the material to be doped is limited to those which are not corroded by the liquid, and an electrochemical reaction of anions in the liquid occurs during doping.
This may accelerate the corrosion of the ceramic to be doped.Because it is performed in a liquid, the liquid penetrates into the ceramic, causing an electrochemical reaction between the electrode and the liquid directly.
Doping may not be possible, doping small parts of ceramics is difficult, and doping-limited metal ions are limited to those that can be dissolved in liquid, and liquid is used in electrolysis system. There are many drawbacks, such as the complexity of the entire device.

[0005] As a supplement to the above-mentioned disadvantage, both ends of the superconducting oxide ceramic are sandwiched between beta-alumina solid electrolytes and electrolysis is performed to replace the metal ions in the superconductor with the metal ions in beta-alumina. (Eg, Hideki Hayashi, Yasumichi Matsumoto, and Tosokichi Honbo (Abstracts of the 1993 Autumn Meeting of Electrochemistry, p.1)
80 (1993)). However, in this method, metal ions are replaced by sandwiching a superconductor to be doped between beta-alumina, which is a metal ion conductor. Therefore, when the ceramic to be heated contains metal ions that are difficult to replace (metal In the case where the bonding force of ions is strong inside the solid), doping is not possible, and if the substitutional doping is forcibly performed, the structure of the ceramic itself may be destroyed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and contains various kinds of cations (metals) in almost all kinds of inorganic solid materials except for a metal material after hardening. When easily implanted, or when the inorganic solid material to be doped contains metal ions with low bonding strength (such as ceramics or glass with high metal ion conductivity), replace the metal ions with any other metal. It is an object of the present invention to provide a method of doping a metal into an inorganic solid material, which is possible.

[0007]

Means for Solving the Problems As a result of earnest studies to solve the above problems, the present inventor has found that an inorganic solid material whose composition is to be controlled is brought into contact with a solid electrolyte material to form an anode.
An electrolytic cell sandwiched between a cathode and a cathode is assembled, and a current is passed through the electrolytic cell under heating so that the metal contained in the solid electrolyte material is subjected to electrolytic injection or electrolytic replacement into the target inorganic solid material whose component is desired to be adjusted. And completed the method of the present invention utilizing electrochemical doping.

[0008] That is, claim 1 of the present invention corresponds to an intrusion (or implantation) type doping system, wherein one side of an inorganic solid material to be doped is a solid containing a metal ion (M ^{n +} ) to be doped. By forming a sandwich electrolytic system in which the solid electrolyte material is brought into close contact with the anode and the other side of the inorganic solid material to be doped is connected to the cathode, and a current is passed between the two electrodes under heating. This is a method for doping a metal into an inorganic solid material, wherein metal ions (M ^{n +} ) contained in a solid electrolyte material on the anode side are electrolytically injected into an inorganic solid material to be doped.

A second aspect of the present invention is that the inorganic solid material to be doped is a solid electrolyte material having high metal ion conductivity (that is, a weak binding force of metal ions inside the solid), and one side of the solid electrolyte material is used as an anode. A sandwich electrolysis system in which the other surface is in close contact with the cathode is formed, and a current is passed between the two electrodes under heating, so that metal M ions (M ^{n +} ) are electrolyzed from the anode into the solid electrolyte material to be doped. This is a method for doping a metal into an inorganic solid material, which is characterized by substitution.

Claim 3 of the present invention corresponds to a metal ion-oxygen ion simultaneous doping system,
One side of the inorganic solid material to be doped is brought into close contact with a solid electrolyte material containing a metal ion (M ^{n +} ) to be doped, and the outside of the solid electrolyte material is used as an anode, while the other surface of the inorganic solid material to be doped is used as an anode. A sandwich electrolysis system in which the outside of the oxygen ion conductive solid electrolyte material is connected to the cathode is formed in close contact with the oxygen ion conductive solid electrolyte material, and a current is applied between the two electrodes under heating to form a solid on the anode side. Metal ions (M ^{n +} ) contained in the electrolyte material,
A metal doping method for an inorganic solid material, characterized in that oxygen ions generated from a cathode are electrolytically injected into an inorganic solid material to be doped at the same time.

A fourth aspect of the present invention is a modification of the third aspect,
A metal ion-oxygen ion simultaneous doping system, wherein an inorganic solid material to be doped is an oxygen ion conductive solid electrolyte material, and a solid electrolyte material containing a metal ion (M ^{n +} ) on one side. And adhere
A sandwich electrolysis system is formed in which the outside of the solid electrolyte material is connected to the anode, and the other surface of the inorganic solid material to be doped is connected to the cathode, and a current is applied between the two electrodes under heating to form a solid on the anode side. Metal ions (M ^{n +} ) contained in the electrolyte material and oxygen ions generated from the cathode are
This is a method of doping a metal into an inorganic solid material, characterized by simultaneously performing electrolytic injection into an inorganic solid material to be doped.

Hereinafter, the configuration of the present invention will be described in detail. The inorganic solid material to be doped according to the present invention includes all metal oxides such as various oxides, dielectrics, and magnetic materials as long as they contain metal ions, glass (particularly various lenses containing SiO ₂ , , Dielectric, light-guiding, ion-sensitive substrates, etc.), or non-oxide ceramics, metal oxide single crystals, and the like. The inorganic solid material to be doped in claim 2 is a solid electrolyte material having high metal ion (cation) conductivity containing an arbitrary metal M ′ other than the substituted metal M, for example, when the metal M ′ is Na ⁺ Beta alumina (M′-β-Al ₂ O ₃ or M′-β ″ -Al ₂ O ₃ ) containing an alkali metal such as an ion or Li ⁺ ion, or an Ag ⁺ ion is mentioned as a preferable example.

The oxygen ion conductive solid electrolyte material according to claim 3 or 4 of the present invention is not particularly limited, but may be zirconia (ZrO ₂ ) or stabilized zirconia (CaO ₂ ).
-ZrO ₂ , Y ₂ O ₃ -ZrO ₂ ) are mentioned as preferable examples. The shape of the inorganic solid material to be doped is not particularly limited, but a plate-like molded product is preferable in terms of handling.

The solid electrolyte material used in the present invention is a solid material having a large ionic conductivity at a low temperature compared to its melting point. For example, a solid electrolyte material such as beta-alumina having a layered structure or stabilized zirconia the substance having a high point defect concentration than solid material position where ions called average structure such as · RbAg ₄ I ₅ system can occupy has significantly more crystalline structure compared to the number of ions, · Li + Al ₂ A substance such as O ₃ in which the transfer of ions is promoted at an interface between two different substances is exemplified.

Particularly preferred solid electrolyte materials include beta alumina (M-β-Al) containing a desired metal cation (M ^{n +} ).
₂ O ₃ , M-β ″ -Al ₂ O _3, etc. Usually, beta alumina containing Na ⁺ ions or Li ⁺ ions (Na-β-Al
₂ O ₃ , Na-β "-Al ₂ O ₃ , Li-β-Al ₂ O ₃ , Li-β" -Al ₂ O ₃
And the like in which the desired metal cation (M ^{n +} ) is substituted in advance for the Na ⁺ ion or Li ⁺ ion of the present invention. Such a solid electrolyte material is preferably a plate-like body having a thickness similar to that of the target inorganic solid material and having a thickness of 3 mm or less, since the solid electrolyte material is in close contact with the inorganic solid material to be doped and the electrolysis voltage must not be so high.

The anode and the cathode used in the present invention are electric conductors which cause an electrochemical reaction, and their materials are not particularly limited as long as they are thermally stable and conductive. However, particularly preferable material for the anode is a metal to be doped.
M or an oxide thereof, or a salt of a metal M. The electrochemical reaction in this case is as follows. For the metal ^{M: M → M n + +} ne - the case of an oxide ^{MO: MO → xM n + +} M 1-x O + xne - whereas Preferred as the material of the cathode, Ag, Pt, Au, RuO 2, Sn
O ₂ and InO ₂ are exemplified. The shapes of the anode and the cathode are not particularly limited, but a plate-shaped anode or a cathode that is in close contact with the solid electrolyte material or the target inorganic solid material is preferable in terms of the efficiency of electrolysis, but these may be formed in any shape other than the plate shape. What adheres to a part, for example, a powder, a sputter film, a plating film, etc. may be sufficient.

The metals to be doped in the present invention include:
In addition to transition metals such as Ag, Cu, and Zn that form metal cations ( ^{Mn +} ), alkali metals such as Li, Na, K, Rb, Cs, and Fr, Ca, Sr, and Ba
And rare earth metals such as La, Nd and Gd. The desired metal cation (M
^{n +} )-containing solid electrolyte material beta alumina (M-β-
Al ₂ O ₃ , M-β ″ -Al ₂ O _3, etc. are beta alumina (Na−) containing alkali metals such as Na ⁺ ions and Li ⁺ ions in advance.
β-Al ₂ O ₃ , Na-β "-Al ₂ O ₃ , Li-β-Al ₂ O ₃ , Li-β"
−Al ₂ O ₃ ) or the like by substituting a desired metal cation (M ^{n +} ) for Na ⁺ ions, Li ⁺ ions, or the like.

[0018] The substitution method is usually carried out by melting beta-alumina (Na-β-Al
₂ O ₃ , Na-β "-Al ₂ O ₃ , Li-β-Al ₂ O ₃ , Li-β" -Al ₂ O ₃
Etc.) It can be easily replaced by immersing the ceramics. In this regard, MSWhittingham an
d RAHuggins literature (J. Electrochem. Soc. 118, 1 (1971)
And GCFarrington and B. Dunn (Solid State Io
nics 7,267 (1982)) and M. Breiter, MM Schreiber and
B. Dunn's reference (Solid State Ionics 18 & 19,658 (1986))
And so on. As a method for replacing metal ions such as beta-alumina, the above-mentioned method is known. Particularly, in the present invention, the desired metal can be electrochemically directly added to such a cation-conductive ceramic. A method capable of electrolytic displacement doping of a cation ( ^{Mn +} ),
In this respect, unlike these known methods, it is epoch-making.

The sandwich electrolysis system of the present invention has only a small system configuration in the case of an intrusion (or implantation) type doping system (claims 1, 3, 4) and in the case of a substitution type doping system (claim 2). A good conductive anode containing at least one side of the target inorganic solid material in contact with a solid electrolyte material (or an electrode plate) containing the metal to be doped, and a metal outside the outside of which is appropriately doped. (Plate) and the other side of one inorganic solid material with or without a solid electrolyte material
(Plate), and both electrodes (plate) form an electric circuit connected to a DC power supply through lead wires. Depending on the shape of the target inorganic solid material, it is desirable to change the shape so that the solid electrolyte material and the outermost electrodes themselves are in close contact with each other.

In the present invention, a constant DC current (or constant voltage) is supplied to such a sandwich electrolysis system under heating (atmosphere) such as an electric furnace or a combustion heating furnace. In particular, according to claims 3 and 4 of the present invention, under the condition that the target inorganic solid material is not decomposed, under an atmosphere containing oxygen (O ₂ or ai
r medium) is required. In claims 1 and 2 of the present invention,
The heating can be performed under various atmospheres (O ₂ , air, N ₂ , H _2, etc.) or under no atmosphere as long as the heating condition does not cause decomposition of the target inorganic solid material.

The heating (atmosphere) temperature in these cases is in the range of 100 to 1300 ° C., preferably 3
The temperature is about 00 to 800 ° C, more preferably about 400 to 600 ° C. When the heating temperature is 100 ° C. or lower, it is not preferable because the ionic conductivity of the solid electrolyte becomes extremely low and the movement of metal ions in the inorganic solid material to be doped becomes extremely low, so that electrolysis becomes difficult. When the heating temperature is 1300 ° C. or higher, it is not preferable in that a part of the beta alumina or the inorganic solid material to be doped is decomposed or a chemical reaction occurs with the solid electrolyte.

The current is sufficient if the current density per unit area of contact between the inorganic solid material to be doped and the solid electrolyte material on the anode side is 10 A / cm ² or less, and preferably 1 A / cm ² or less.
It is about 0 ^-7 to 10 ^-2 A / cm ² . When doping is performed by electrolysis at a constant voltage, the voltage is preferably a voltage of 10 ⁴ V or less. The current density is 10 ^-7
A / cm ² or less is not preferable because the amount of the doped metal is too small. On the other hand, if the current density is 10 A / cm ² or more, the type of metal cation (M ^{n +} ) is not preferable in that the structure of the grain of the inorganic solid material to be doped or the grain boundary is destroyed.

By applying a current under such heating, metal cations contained in the solid electrolyte material on the anode side are electrolytically injected into the target inorganic solid material by an electrochemical reaction or as cations (M ^{n +} ). You. At this time, the grain boundary doping and the intragranular (intracrystalline) doping of the inorganic solid material of the metal cation can be controlled by the magnitude of the current. Another feature is that the amount of metal ion doping can be controlled by the amount of electricity required for electrolysis.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to specific examples. FIG. 1 is a model diagram showing an example of a sandwich electrolysis system corresponding to an intrusion (injection) doping system in claim 1 of the present invention. In FIG. 1, A is an inorganic solid material to be doped, and B is A
Metal ion to be doped (M
^{n +} )-containing beta-alumina-based solid electrolyte material (eg, M-
β-Al ₂ O ₃ , M-β "-Al ₂ O ₃ etc.) and C is an anode connected to the outside of B, such as a plate, powder or a sputtered or plated film. In particular, it is preferable to select from a metal M to be doped or an oxide containing a metal M ion or a salt thereof, but it is preferable to select another metal (eg, Ag) or an oxide thereof. The other side (right side) of A is directly connected to a lead wire to serve as a cathode of a counter electrode. Same as C or Ag or Pt on the surface side
It is preferable to attach a plate-shaped cathode of good conductivity, such as.

When a current is applied to the sandwich electrolysis system shown in FIG. 1 under heating of an electric furnace or the like, M ^{n +} ions are injected from the anode C into the beta alumina of B by electrochemical oxidation, and the M ^{n +} ions of B are It is electrolytically injected into the target inorganic solid material A. That is, in this system, M ^{n +} ions are doping due to excessive electrolytic implantation into the target inorganic solid material A. That is, in principle, the following electrochemical reaction occurs in the doping target A. However doping object ceramics A and When ^{M'O M'O + xM n + + xne} - The M ^{n +} ions at the → M'M _x O (M is doped directly M'O) this system, a small ionic radius Metal ions such as Li ⁺ and Mg ²⁺ ions are preferred. In the case where the anode C is a metal N or an oxide containing a metal ion N ^{n +} different from the oxide containing a metal M or a metal ion M ^{n +} or a salt thereof to be doped, or a salt thereof, He N ^{n +} ions are electrolytically implanted, and M ^{n +} ions of B are electrolytically implanted into the inorganic solid material A to be doped.

FIG. 2 is a model diagram showing an example of a sandwich electrolysis system corresponding to a substitutional doping system for a solid electrolyte material having high metal ion (cation) conductivity in claim 2 of the present invention. As a material of the cathode E in the figure, a metal having a high melting point and hardly oxidizing (for example, Ag,
Au, Pt, etc.) are desirable. B 'and C' are similar to B and C described in FIG. 1, except that B '
And various metals different from the cations to be substituted. Various metals as B '
M 'metal ions (cations) conducting a high beta-alumina _{(M'-β-Al 2 O} 3, M'-β "-Al 2 O 3 , etc.) containing preferably, the metal M' is a metal to be doped The cation to be replaced with M, generally an alkali metal or Ag.The plate-shaped anode C 'needs to contain the metal M to be doped, so that the metal M or its metal oxide is used. Alternatively, it must be selected from its salts.

When a current is passed through the sandwich electrolysis system shown in FIG. 2 while heating in an electric furnace or the like, the solid electrolyte material to be doped B 'is converted from the anode C' by an electrochemical oxidation reaction.
M ^{n +} is electrolytically injected. At the same time, the ions of the metal M 'previously contained are electrochemically reduced at the cathode E, and M'
The metal or its oxides or carbonates precipitate. That is, in principle, the following electrochemical reaction occurs in the doping target B ′. In ^{xM n + + M'O → M '} 1-x M x O + xM' n + The cathode E is reduced as follows. ^{xM 'n + + xne - →} xM' ( Note M 'is in air is an alkali metal such as Na, 2Na
+ 1 / 2O ₂ → Na ₂ O, and further Na ₂ O + CO ₂ → Na ₂ CO ₃ . As described above, at least a part of the ions of the metal M ′ in B ′ is electrolytically replaced with the M ions.

FIG. 3 is a model diagram showing an example of a sandwich electrolysis system corresponding to the metal ion-oxygen ion simultaneous doping system according to claim 3 of the present invention.
A, B, and C in FIG. 3 have the same configuration as that described in FIG. 1, but in this case, an oxygen ion conductive solid electrolyte material F is adhered to the other surface of the inorganic solid material A to be doped. The difference is that this is a sandwich electrolysis system in which the outside of the oxide is connected to a plate-like cathode G. In this case, as F, an oxide ceramic having high oxygen ion conductivity or an oxygen ion conductor (for example, zirconia (ZrO ₂ ) or stabilized zirconia such as Y ₂ O ₃ or CaO-containing ZrO ₂ ) is preferable. Any oxide having high ion conductivity may be used. As a material of the cathode G, an electrode catalyst (for example, Pt or the like) capable of promoting an electrochemical reduction reaction (that is, O ₂ + 4e ⁻ → 2O ^2- ) of O ₂ molecules to O ²⁻ ions is preferable.

When a current is applied to the sandwich electrolysis system shown in FIG. 3 under heating of an electric furnace or the like, ^{Mn +} ions are electrolytically injected from the electrode C to the beta alumina of B by the electrochemical oxidation reaction, and B ^{Mn +} ions are electrolytically implanted into the inorganic solid material A to be doped, and the cathode G
Ions are implanted into the F from the O (electrochemical reduction of O ₂ molecules to O ²⁻ ions (in the oxide F) at the cathode G), and oxygen ions are supplied from the F to the inorganic solid material A to be doped. Is done. That is, the metal ions M ^{n +} and oxygen ions O ²⁻ are simultaneously supplied and doped into the inorganic solid material A for doping, so that there is no replacement of metal ions. Oxygen ions become oxides and are present in excess.

That is, in principle, the following electrochemical reaction occurs in the doping target A (however, the doping target ceramic A is M'O). (Anode beta-alumina ^{side: M'O + xM n + + xne} - → M'M
_x O (cathode ZrO ₂ side: (nx / 2) O ^2- + M'M _x O → M'M _x O _{1 + nx / 2}
+ XNE ^- total ^{reaction: M'O + xM n + + (} nx / 2) O 2- → M'M x O
_{1 + nx / 2} (Material to be doped) In addition, the oxygen ion implantation promotes the metal ion implantation to electrically neutralize the positivity in the solid material to be doped by the metal ion implantation. ).

FIG. 4 is a model diagram showing an example of a sandwich electrolysis system corresponding to a modification of the metal ion-oxygen ion simultaneous doping system according to claim 4 of the present invention. B and C in the figure have the same configuration as those described in FIG. 1, except that in this case, the oxygen ion conductive solid electrolyte material F described above is used as the doping inorganic solid material. The material of the plate-like cathode G on the other side of the sandwich electrolysis system is the same as that described with reference to FIG.

When a current is passed through the sandwich electrolysis system shown in FIG. 4 under the heating of an electric furnace or the like, ^{Mn +} ions are electrolytically injected from the anode C to the beta alumina of B by the electrochemical oxidation reaction as described above. Of M ^{n +} ions are implanted into the oxygen ion conductive solid electrolyte material of F (for example, stabilized zirconia). On the other hand, oxygen is simultaneously injected from the cathode G as ions into the stabilized zirconia of F (at the cathode G, O ₂ molecules are electrochemically reduced to O ²⁻ ions (in the oxide F)). Thus, the target inorganic solid material F is doped while the metal ions M ^{n +} and the oxygen ions O ²⁻ are supplied simultaneously.

The implantation of oxygen ions has the effect of rendering the implanted metal ions electrically neutral. In the case of substitution of a metal ion, the electric neutrality is maintained by the substitution, but in this case, the oxygen ion plays a role. That is, also by supplying oxygen ions here,
Since the metal ions are implanted without reducing the Zr ⁴⁺ ions in F, the doping of the metal ions becomes easier. In this case, the following electrochemical reaction occurs in the doping target F. M ^{n ++} (n / 2) O ²⁻ → MO _{n / 2, that} is, doping to stabilized zirconia F becomes possible.

[0034]

EXAMPLES Specific examples of the present invention will be described below. The inorganic solid material A for doping, the solid electrolyte material B, and the like shown in the following examples were adjusted as follows.・ As the inorganic solid material A to be doped, YBa ₂ Cu ₃ Oy
Using a superconductor (hereinafter abbreviated as YBCO) or Fe ₂ O ₃ ceramics, adjustment was performed as follows. That is, in the case of YBCO, Y ₂ O ₃ , BaCO ₃ and CuO were used as starting materials, and this mixture was fired at 930 ° C. for 10 hours, reground, and fired again under the same conditions. This is pressed at a pressure of 1000 kg / cm ² , fired at 930 ° C., and a sample of YBCO pellets (thickness:
1.5 mm, surface area: 1.5 cm ² ). On the other hand, when the Fe ₂ O _3, after pressing the powder of Fe ₂ O ₃ at a pressure of 1000 Kg / cm ^2, then sintered for 5 hours at 900 ° C., the pellet (thickness: 1.5 mm,
Surface area: 1.5 cm ² ).

The solid electrolyte material B is made of Na-β "-Al ₂ O ₃
a is replaced by various metals M (K ⁺ , Ca ²⁺ , Sr ²⁺ , Ag ⁺ , Zn ²⁺ ) and ^prepared beta-alumina (M-β ") containing metal M ions
Using the -Al ₂ O _3). The presence of M in these solid electrolyte materials was confirmed by EPMA analysis. -Ag or Zn is used as the material of the anode electrode plate C,
On the other hand, Ag or Pt was used as the material of the cathode electrode plates E and G.

Example 1 An example using a modified metal ion-oxygen ion simultaneous doping system shown in FIG. 4 will be described. The inorganic solid material F to be doped is Zr containing Y (8 mol% as Y ₂ O ₃ ).
O ₂ was used and doped with Zn. The electrolysis conditions in this case are as follows: B: Zn-β ″ -Al ₂ O ₃ , F: Y-containing stabilized zirconia (Zr containing 8 mol% as Y ₂ O ₃
O ₂ ), C anode: zinc (Zn), G cathode: Pt, heating atmosphere temperature: 400 ° C., constant current: 10 ^-4 A (current density: 4 × 10 ^-4 A)
/ Cm ² ) for 3 hours, each contact area of C, B, F, G:
0.25 cm ² . When an electrolysis current was passed through the sandwich electrolysis system shown in FIG. 4, the electrolysis voltage gradually increased to several hundred volts.

The cation distribution on the cross section of the ceramics F after electrolysis was analyzed by EPMA. That is, the element distribution diagram showing the respective concentration states of Zn, Na, O and Zr in the cross section in the thickness direction (3000 times) of stabilized zirconia doped with Zn (irradiation electrons are acceleration voltage: 15 KV, irradiation beam current: 5 × 10 ^-8 A, analytical characteristics X-rays are Zn: K _α- ray, Na: K _α- ray, Zr: L _α- ray, O: K
As a result of examining the electron micrograph of ( _α- ray), it was confirmed that Zr and O were present in a large amount at the same time as the amount was small but Zn was surely present uniformly in the thickness direction. As a result of analyzing the element concentrations before and after electrolysis, Zn in the ceramics was not detected at 0 mol% at all before electrolysis, but after electrolysis, the Zn element was about 2 mol% (in terms of ZnO). Had been doped.

Example 2 The element concentration of a ceramic doped with Mg before and after electrolysis was analyzed using the intrusion (injection) doping system shown in FIG. The material used is B
Mg-β "-Al ₂ O ₃ , YBCO ceramics were used as A, and silver was used as C. The electrolysis conditions in this case were A;
a ₂ Cu ₃ Oy, B: Mg-β ″ -Al ₂ O ₃ , C anode: silver (Ag), heated atmosphere temperature: 600 ° C., constant current: 10 ⁻³ A (current density: 4
× 10 ^-3 A / cm ² ) for 1 hour, contact area between A and B: 0.
It is a 25cm ^2. The same silver (Ag) as the C anode was used for the cathode on the other side of A. Also in this case, similarly to the first embodiment described above.
It was confirmed by EPMA that Mg was uniformly doped in the whole YBa ₂ Cu ₃ Oy. In addition, as a result of analyzing the element concentrations before and after the electrolysis, the Mg element in the ceramics was 0 mol% before the electrolysis, but after the electrolysis,
The Mg element was doped at about 1 mol% (in terms of MgO).

Example 3 An example using the substitutional doping system for the cation conductor shown in FIG. 2 will be described. In addition, silver (Ag) was used for the E cathode, and silver (Ag) and sodium beta alumina (Na-β ″ -Al ₂ O ₃ ) were used for C ′ and B ′, respectively. is, B ': Na-β " -Al 2 O 3, C' anode: silver (Ag), E cathode: silver (Ag), heating temperature: 600 ° C., a constant current: 10 ^-3 A (current density: 4 × 10 ^-3 A / cm ² )
Time, contact area between B ′ and C ′, E: 0.25 cm ² .
In this case as well, as in Example 1, it was confirmed by EPMA analysis that Ag was uniformly doped into the whole B ′ beta alumina. Analysis of the element concentrations before and after electrolysis showed that before electrolysis, Ag
Was not detected at 0 mol%, but after electrolysis,
The Ag element was doped at about 5 mol% (in terms of Ag metal or AgO).

Embodiment 4 An embodiment using the metal ion-oxygen ion simultaneous doping system shown in FIG. 3 will be described. Note that Fe ₂ O ₃ was used as the ceramic A to be doped, and this was doped with Zn. The C anode used was the same Zn as in Example 1, the F used was the same stabilized zirconia (Y-containing ZrO ₂ ) as in Example 1, and the G cathode was Pt. The electrolysis conditions in this case include:
A: Fe ₂ O ₃ , B: Zn-β ″ -Al ₂ O ₃ , F: Y-containing (Y ₂ O ₃
8 mol%) ZrO ₂ , C anode: Zn, G cathode: Pt
The heating atmosphere temperature was 400 ° C., the constant current was 10 ⁻⁴ A (current density: 4 × 10 ⁻⁴ A / cm ² ) for 1 hour, and the contact area between A, B and F was 0.25 cm ² . Also in this case, it was confirmed by EPMA analysis that Zn was uniformly doped in the whole Fe ₂ O ₃ as in Example 1. Also, as a result of analyzing the element concentrations before and after electrolysis, before the electrolysis, Zn in the ceramics was not detected at all at 0 mol%,
After the electrolysis, the Zn element was doped at about 1 mol% (in terms of ZnO).

[0041]

According to the above-described method of the present invention, even if almost all kinds of inorganic solid materials except for the metal material which have been hardened once are injected with a desired cation (metal) into the inside, or It is possible to easily replace the metal originally contained in the inorganic solid material having high metal ion conductivity with any other metal. As a result, new properties and functions can be imparted to the inorganic solid material, so that it can be applied to various functional material fields such as electric / electronic materials, nuclear reactor materials, mechanical components, abrasives, heat insulating materials, and glass substrate materials. This is a potential invention.

[Brief description of the drawings]

FIG. 1 is a model diagram showing an intrusion (injection) doping system of the present invention.

FIG. 2 is a model diagram showing a system for replacing metal ions in beta alumina of the present invention.

FIG. 3 is a model diagram showing a metal ion-oxygen ion simultaneous doping system of the present invention.

FIG. 4 is a model diagram showing a system for simultaneously doping metal ions and oxygen ions into zirconia in a modification of FIG. 3;

[Explanation of symbols]

A Inorganic solid material to be heated B Solid electrolyte material containing metal ions M ^{n + to be} heated B 'Solid electrolyte material with high metal ion conductivity to be heated C, C' Anode E Cathode F Oxygen ion conductive solid electrolyte material G Cathode

Claims (10)

[Claims] 1. One side of an inorganic solid material to be doped is brought into close contact with a solid electrolyte material containing a metal ion (M ^{n +} ) to be doped. An inorganic solid material to be doped with metal ions ( ^{Mn +} ) contained in the solid electrolyte material on the anode side by forming a sandwich electrolysis system with the surface side connected to the cathode and passing current between both electrodes under heating A method for doping a metal into an inorganic solid material, wherein the metal is electrolytically injected therein. 2. A sandwich electrolytic system in which an inorganic solid material to be doped is a solid electrolyte material having high metal ion conductivity, one side of which is in close contact with an anode, and the other side of which is in close contact with a cathode is formed. A metal doping method for an inorganic solid material, wherein a metal M ion (M ^{n +} ) is electrolytically substituted into a solid electrolyte material to be doped from an anode by flowing a current between both electrodes. 3. One side of the inorganic solid material to be doped is brought into close contact with a solid electrolyte material containing a metal ion (M ^{n +} ) to be doped, and the outside of the solid electrolyte material is used as an anode, while the inorganic solid material to be doped is used as an anode. The other side is in close contact with the oxygen ion conductive solid electrolyte material to form a sandwich electrolysis system in which the outside of the oxygen ion conductive solid electrolyte material is connected to the cathode, and a current flows between both electrodes under heating. Metal doping of the inorganic solid material, characterized in that metal ions (M ^{n +} ) contained in the solid electrolyte material on the anode side and oxygen ions generated from the cathode are simultaneously electrolytically injected into the inorganic solid material to be doped. Method. 4. An inorganic solid material to be doped is an oxygen ion conductive solid electrolyte material, one surface of which is in close contact with a solid electrolyte material containing a metal ion (M ^{n +} ), and an outer surface of the solid electrolyte material. To the anode, while forming a sandwich electrolysis system in which the other side of the inorganic solid material to be doped is connected to the cathode, by passing a current between the two electrodes under heating, the metal contained in the solid electrolyte material on the anode side A metal doping method for an inorganic solid material, wherein ions ( ^{Mn +} ) and oxygen ions generated from a cathode are simultaneously electrolytically injected into an inorganic solid material to be doped. 5. The inorganic solid material to be doped is selected from the group consisting of metal oxide ceramics, non-oxide ceramics, glass, and metal oxide single crystals. 3. The method for doping a metal into an inorganic solid material according to item 1. 6. A beta-alumina (M′-β-Al ₂ O ₃ or M′-β-Al ₂ O ₃ containing a metal M ′ different from a metal M to be doped by a solid electrolyte material having high metal ion conductivity to be doped.
_{3. The} method for doping a metal in an inorganic solid material according to claim 2, wherein the method is M'-β "-Al ₂ O ₃ ). 7. The oxygen ion conductive solid electrolyte material is zirconia (ZrO ₂ ) or stabilized zirconia (CaO—Zr).
_{O 2, Y 2 O 3 -ZrO} 2 , etc.) are those selected from claim 3 or 4 metal doping method to inorganic solid material according. 8. The material of the anode is metal M to be doped.
The method for doping a metal in an inorganic solid material according to any one of claims 1 to 4, wherein the method is selected from the group consisting of an oxide thereof and a salt of a metal M. 9. The solid electrolyte material is beta alumina (M-β-Al ₂ O ₃ or M-β ″ -Al ₂ O ₃ ) containing metal M ^{n +} ions.
The method for doping a metal into an inorganic solid material according to claim 1, wherein the method is a system. 10. The electrolytic doping has a heating temperature of 100.
The method for doping a metal in an inorganic solid material according to any one of claims 1 to 4, wherein the method is carried out at a temperature of 1 to 1300 ° C and a current density of 10 A / cm ² or less.