JPS5943425B2 - Compound having hexagonal layered structure represented by TmFeZnO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound TmFeZnO4 having a hexagonal layered structure and a method for producing the same.

Conventionally, compounds having a hexagonal layered structure represented by YFe and O4 have been synthesized by the present applicants, and their existence is already known.

In this compound, as shown by Y_3fFe+Fe_3f0_2-, the divalent and trivalent ions of iron are 5
Surrounded by coordinating oxygen ions, yttrium (Yl
) It is a compound that has six-coordinated oxygen ions around it and is magnetic. The present invention relates to the above-mentioned Y_3f
The purpose of the present invention is to provide a new compound in which Y_3+ of the compound o is replaced with Tm_3' and Zn_2f is replaced with Fei, and a method for producing the same.

In the compound represented by TmFeZnO4 of the present invention, thulium is a Tm"+ ion, and iron is a 5Fe_3+
, zinc exists as Zn_2゛9, Tm_3f
It can be expressed as Fe_3ArZn_2fq-.

This crystal has a hexagonal layered structure as shown in FIG. The largest circle is oxygen, the middle circle is thulium, and the black circles are iron and zinc. Zinc'0 lead and iron are randomly distributed. The divalent ion of zinc and the trivalent ion of iron are surrounded by five-coordinated oxygen ions. Crystallographically, they occupy the same position. Also, thulium is 6
It has coordinating oxygen around it. Oxygen, which is an anion, has a dense five-packed structure. s, and u indicate the position within the unit cell. This crystal plane index (hk
l), interplanar spacing (d(A)) [do ratio l, dc indicate calculated values], relative reflection intensity with respect to X-rays, 1 (to) are as shown in Table 1.

■0 Table 1 TmFeZn04 ζ5 The space group is R3m' (: exists, its crystal habit is plate-like,
The lattice constants are 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 metal iron, or a compound that decomposes into iron oxide (Fe2O3) when heated, and zinc or zinc oxide (ZnO), or a compound that decomposes into iron oxide (Fe2O3) when heated. A compound that produces zinc oxide (ZnO) is mixed with thulium, iron, and zinc in an atomic ratio of 1:1:1, and the mixture is exposed to an oxidizing atmosphere in the air at a temperature of 1200°C or higher. , or iron and zinc are each in the trivalent ion state, 2
It can be produced by heating in a reducing atmosphere that does not reduce the valence ion state.

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 the starting material is less than or equal to m. When used as a magnetic material, contamination with impurities is avoided, so the higher the purity of the starting raw material, the more preferable it is.

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 zinc is 1:1:1. If this ratio is exceeded, it will not be possible to obtain the desired compound. This mixture is stored in the air or in an oxidizing atmosphere or when iron and zinc are in the trivalent ion state and in the divalent ion state.
Heating is carried out at a temperature of 1200° C. or higher in a reducing atmosphere that prevents reduction from the valence ion state. The heating time is
One day or more. There are no rules regarding the rate of mud rise during heating. After the reaction is completed, it may be rapidly cooled to 0°C or rapidly drawn out into the atmosphere. The obtained ′RnlF
The eznO compound exhibited a brown 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 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. Examples Thulium oxide (Tm2Os,
) powder, iron oxide (Fe2O2) powder with a purity of 99.9% or more, and reagent grade zinc oxide (ZnO) powder at a molar ratio of 1:1:2, and mixed them with ethyl alcohol in a floating pot. The mixture was added and thoroughly mixed to obtain a fine powder with an average particle size of several μm.

The mixture was filled in a platinum crucible and placed in a box-shaped siliconite furnace set at 13,500C and heated for 4 days, after which the sample was taken out of the furnace and rapidly cooled to room temperature. The obtained sample was TmFeZnO, and it was confirmed by powder X-ray diffraction that it was crystallographically the same type as the previously reported YFe2O4. The sample weight was carefully 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 TnlFeZnO4 crystal of the present invention.

Claims (1)

[Claims] 1 A compound having a hexagonal layered structure represented by TmFeZnO_4. 2 Thulium metal (Tm) or thulium oxide (Tm
_2O_3) or a compound that decomposes into thulium oxide (Tm_2O_3) when heated; metal iron (Fe) or iron oxide (Fe_2O_3) or a compound that decomposes into iron oxide (Fe_2O_3) when heated; Zinc (Zn) or zinc oxide (ZnO
) or a compound that is decomposed to produce zinc oxide (ZnO) when heated, so that the atomic ratio of thulium, iron, and zinc is 1:1:1.
A hexagonal material represented by TmFeZnO_4, which is heated in the air at a temperature of 00°C or higher in an oxidizing atmosphere or in a reducing atmosphere to the extent that iron and zinc are not reduced more than the trivalent ion state and the divalent ion state, respectively. A method for producing a compound having a crystalline layered structure.