JPS5943424B2 - Compound having hexagonal layered structure represented by TmFeCuO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound TmFeCuO4 having a hexagonal layered structure and a method for producing the same.

Conventionally, a compound having a hexagonal layered structure represented by YFe_204 was synthesized by the present applicants, and its existence is already known.

This compound is Y_3+Fe_2+Fe_3+04_2
As shown by -, divalent and trivalent ions of iron are surrounded by five-coordinated oxygen ions, and yttrium is a compound that has six-coordinated oxygen ions around it. , has magnetism. The present invention relates to the above-mentioned Y_
The object of the present invention is to provide a novel compound in which Y_3+ of the compound 3+Fe'+Fe_3+04' is replaced with Td+, and Cu''+ is replaced with Fe_2+, and a method for producing the same.

In the compound represented by TmFeCu04 of the present invention, iron exists as Fe_3+ ion, thulium exists as T-+, copper exists as Cu_2+, and Tm_3+Fe_3
+Cu_2+04_2-.

This crystal has a hexagonal layered structure as shown in FIG. The largest circle indicates oxygen, the middle circle indicates thulium, and the smallest black circle indicates Fe and copper. Fe and Cu are randomly distributed. The divalent ion of copper and the trivalent ion of iron are
Surrounded by five-coordinated oxygen ions. Crystallographically, they occupy the same position. Moreover, Tm has six-coordinated oxygen around it. Oxygen, an anion, has a dense structure. s, and u indicate the position within the unit cell. This crystal has a plane index (hkl), a plane spacing (d
(A)) [do indicates actual measurement, dc indicates calculated value.

], the relative reflection intensity for X-rays, I(96), are as shown in Table 1. The space group is R, the crystal habit is plate-like, and the lattice constant is as follows.

This compound is useful as a magnetic material, a semiconductor material, and a catalyst.

This compound can be produced by the following method.

Thulium metal (Tm) or thulium oxide (Tm2O
3) Alternatively, thulium oxide (
A compound that decomposes into iron oxide (Fe2O3) and metallic iron, or a compound that decomposes into iron oxide (Fe2O3) when heated, and copper or copper oxide (CuO), or a compound that decomposes into iron oxide (Fe2O3) when heated. A compound that produces copper oxide (CuO) is mixed with thulium, iron, 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 800°C or higher. Alternatively, it can be produced by heating in a reducing atmosphere to the extent that iron and copper 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 rapidly advance the chemical reaction between the starting materials, the particle size should be as small as possible, especially 10 μm.
It is preferable that it is below m.

Further, when used as a magnetic material or an electric material, since contamination with impurities is avoided, it is preferable that the starting material has a higher purity.

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 thulium, iron, and copper is 1:1:1.

If this ratio is exceeded, the target compound cannot be obtained. This mixture was heated for 800 min in air, or in an oxidizing atmosphere or in a reducing atmosphere such that iron and copper could not be reduced from their trivalent and divalent ionic states.
Heat at temperatures above ℃. 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, it may be rapidly cooled to 0°C or rapidly drawn out into the atmosphere. The obtained TmFeCuO4 compound is
It exhibited a black color and was found to have a crystalline structure by powder X-ray diffraction. It was found that its crystal structure was the same as that of YFe2O4, which had already been 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 Thulium oxide (Tm2O3) powder with a purity of 99.9% or more, purity 99.9%
Weigh out the above iron oxide (Fe2O3) powder and reagent-grade copper oxide (CuO) powder at a molar ratio of 1:1:1, add ethyl alcohol in a mortar and mix thoroughly to obtain an average particle size. A fine powder with a diameter of several μm was obtained.

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 TmFeCuO4, and it was confirmed by powder X-ray diffraction that it was crystallographically the same type as the previously reported YFe2O4. 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 an illustration of a TmFeCuO4 crystal of the present invention.

Claims (1)

[Scope of Claims] 1 A compound having a hexagonal layered structure represented by TmFeCuO_4. 2 Thulium metal (Tm) or thulium oxide (Tm
_2O_3) or a compound that is decomposed into thulium oxide (Tm_2O_3) by heating, and metallic iron (Fe) or iron oxide (Fe_2O_3), or
A compound that decomposes into iron oxide (Fe_2O_3) when heated, and copper (Cu) or copper oxide (CuO)
Alternatively, it is decomposed by heating to produce copper oxide (C
A compound that produces uO) is mixed with thulium, iron, and copper in an atomic ratio of 1:1:1, and the mixture is heated in an oxidizing atmosphere or in an oxidizing atmosphere in the air at a temperature of 800°C or higher. T characterized by being heated in a reducing atmosphere that does not reduce the trivalent ion state or the divalent ion state.
A method for producing a compound having a hexagonal layered structure represented by mFeCuO_4.