JPS606892B2 - Compound having hexagonal layered structure represented by YbGaCuO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound YbGaCu04 having a hexagonal layered structure and a method for producing the same.

Conventionally, a compound having a hexagonal layered structure represented by YFe204 was synthesized by the present applicant, and its existence is already known.

In this compound, as Y30Fe is shown as Fey042-, divalent and trivalent iron ions are surrounded by five-coordinated oxygen ions, and yttrium (Y) has six-coordinated oxygen ions. It is a compound that has around it,
It has magnetism. The present invention provides the above-mentioned Y3NaFe20F
e30042-Yb30 instead of Y20 in the compound, F
It is an object of the present invention to provide a novel compound in which e20 is replaced by C〆0 and Fe30 is replaced by Ga30, and a method for producing the same.

In the compound represented by YMaCu04 of the present invention, ytterbium is Yb30 ion, gallium is G
a30, copper exists as Cu20, Y is 10Ga
It can be expressed as 30Cu2042-.

This crystal has a hexagonal layered structure as shown in FIG. The largest circle indicates oxygen, the middle circle indicates ytterbium, and the smallest black circle indicates gallium and copper. Gallium and copper are
Randomly distributed. The divalent ions of copper and the trivalent ions of gallium are surrounded by five-coordinated oxygen ions. Crystallographically, they occupy the same position. Moreover, Yb has hexacoordinated oxygen around it. Oxygen, an anion, has a delicate structure. s, t and u indicate positions within the unit cell. This crystal plane index (hkl
), surface spacing (d(A)) [do is actually measured, dc is calculated value.

], relative reflection intensity for X-rays, 1 (%) are as shown in Table 1. YbGaou04 The first table space group is Rim, its crystal habit is plate-like, and its lattice constant is as follows.

ao=3.4601 ±0.0004 (
A) CO=24.172 Sat 0.006
(A) This compound is useful as a semiconductor material and a catalyst.

This compound can be produced by the following method.

Ytterbium metal (Yb) or ytterbium oxide (YQ03), or a compound that decomposes into ytterbium oxide (YQ03) when heated, and gallium metal or gallium oxide (Ga203). (Ga203
) and metallic copper or oxidized steel (Cu
○) or decomposed by heating to produce oxidized steel (
Cuo) is mixed with a compound that produces ytterbium, gallium, and copper in an atomic ratio of 1:1:1, and the mixture is heated in an oxidizing atmosphere in the air at a temperature of 700 oo or more.
Alternatively, gallium and copper can be produced by heating in a reducing atmosphere to the extent that they are not reduced from the trivalent ion state or the divalent ion state, respectively.

As the starting materials used in the present invention, commercially available ones may be used as they are, but in order to speed up the chemical reaction between the starting materials, the smaller the particle size, the better.
It is preferable that it is below m.

Furthermore, when used as an electrical material, contamination with impurities is avoided, so the higher the purity of the starting material, the better.

This raw material is thoroughly mixed as is or with alcohol or acetone. The mixing ratio of these is such that the atomic ratio of ytterbium, gallium, and copper is 1:1:1.

If this ratio is exceeded, the target compound cannot be obtained. This mixture was mixed in air, or in an oxidizing atmosphere or in a reducing atmosphere such that gallium and copper could not be reduced from their trivalent and divalent ionic states.
Heat at a temperature of 00°C or higher. The heating time is one day or more. There are no restrictions on the rate of temperature increase during heating. After the reaction is completed, the temperature may be raised to 0° C. or the solution may be rapidly drawn out into the atmosphere. The obtained YbGaCu04 compound exhibited a black color and was found to have a crystal structure by powder X-ray diffraction. It was found that its crystal structure was the same as that of YFe204 already obtained by the applicant. The weights of the starting mixed sample and the reaction product were precisely weighed, and the stoichiometry of the resulting sample was determined. Example: Ytterbium oxide (YQ03) with a purity of 99.9% or more
) powder, gallium oxide (Ga20
3) Powder and reagent grade oxidized steel (Cu○) powder,
The mixture was weighed at a molar ratio of 1:1:2, and ethyl alcohol was added in a mortar and thoroughly mixed to obtain a fine powder with an average particle size of several meters.

The mixture was placed in a platinum crucible, placed in a box-shaped siliconite furnace set at 1020°C, and heated for 4 days.
Thereafter, the sample was taken out of the furnace and rapidly cooled to room temperature. The obtained sample was Y-expanded ACu04, and it was confirmed by powder X-ray diffraction that it was crystallographically the same type as the previously reported YFe204. The weight of the sample was precisely weighed before and after heating, and the stoichiometry of the resulting sample was determined. Table 1 shows the crystallographic properties of the samples obtained.

[Brief explanation of drawings]

The drawing is a diagram of the YbGaCu04 crystal of the present invention. The largest circle indicates oxygen, the middle circle indicates ytterbium, and the smallest black circle indicates gallium and copper. Traditional drawing 1

Claims (1)

[Scope of Claims] 1 A compound having a hexagonal layered structure represented by YbGaCuO_4. 2 Metallic ytterbium (Yb) or ytterbium oxide (Yb_2O_3), or a compound that decomposes into ytterbium oxide (Yb_2O_3) when heated, and metallic gallium (Ga) or gallium oxide (Ga_2O_3) or a compound that is heated. Copper (Cu) or copper oxide (CuO), or a compound that decomposes to produce copper oxide (CuO) when heated, is combined with ytterbium, gallium, Mix copper so that the atomic ratio is 1:1:1, and at a temperature of 700°C or higher in the air, in an oxidizing atmosphere, or in an oxidizing atmosphere, gallium and copper are not reduced from the trivalent ion state and the divalent ion state, respectively. 1. A method for producing a compound having a hexagonal layered structure represented by YbGaCuO_4, which comprises heating in a moderately reducing atmosphere.