JPH0435408B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a compound having a hexagonal layered structure represented by InFeZn ₅ O ₈ , which is a new compound useful as a magnetic material, a semiconductor material, a catalyst material, etc., and a method for producing the same. Conventional technology Conventionally, (Yb ³⁺ Fe ³⁺ O ₃ ) _o Fe ²⁺ O (n indicates an integer)
The compound having a hexagonal layered structure represented by is synthesized by the applicant and is known. YbFe ₂ O ₄ , Yb ₂ Fe ₃ O ₇ , Yb ₃ Fe ₄ O ₁₀ and Yb ₄ Fe ₅
Lattice constant of O ₁₃ as hexagonal system, YbO _1.5 layer,
Table 1 shows the number of layers in the unit cell of _1.5 FeO layers and _2.5 Fe ₂ O layers. These compounds have a layered structure in which YbFeO ₃ is thought to be combined at a ratio of n moles (n=1, 2, 3...) per mole of iron oxide (FeO).

[Table] Purpose of the invention The present invention is based on the chemical formula of (YbFeO ₃ ) _o FeO,
Corresponds to n = 1/5, In ³⁺ instead of Yb ³⁺ , Fe ²⁺
The object of the present invention is to provide a novel compound obtained by replacing Zn ²⁺ in place of Zn 2+ . Structure of the Invention In the ionic crystal model, the compound represented by InFeZn ₅ O ₈ of the present invention is In ³⁺ (Fe ³⁺ , Zn ²⁺ )Zn ₄ ²⁺ O ₈ ^2-
The structure is InO _1.5 layer, (Fe, Zn)
It is formed by stacking an O _2.5 layer and a ZnO layer, and one of its characteristics is that it has significant structural anisotropy. One-fifth of the Zn ²⁺ ions together with Fe ³⁺ form the (Fe ³⁺ , Zn ²⁺ )O _2.5 layer, and the remaining 4/5 form the ZnO layer. The lattice constants as a hexagonal crystal system are as follows. a=3.288±0.001 (Å) c=57.28±0.01 (Å) Planar index (hkl), interplanar spacing (d (Å)) of this compound
(d _p is an actual measured value, d _c is a calculated value) and the relative reflection intensity (I (%)) for X-rays is shown in Table 2. This compound is useful as a magnetic material, a semiconductor material, and a catalytic material. For example, it is possible to use them as magnetic materials, semiconductors, and catalyst materials that have two-dimensional properties with strong anisotropy.

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[Table] This compound can be produced by the following method. Metallic indium or indium oxide or a compound that decomposes into indium oxide when heated; Metallic iron or iron oxide or a compound that decomposes into iron oxide when heated; Metallic zinc or zinc oxide or a compound that decomposes into zinc oxide when heated. are mixed in an atomic ratio of In, Fe, and Zn in an atomic ratio of 1:1:5, and the mixture is heated at a temperature of 650°C or higher in the air, an oxidizing atmosphere, or an In
and Fe in a trivalent ion state, and Zn in a divalent ion state by heating in a reducing atmosphere in which they are not reduced. Commercially available starting materials may be used as they are, but in order for the chemical reaction to proceed quickly, it is better to have a small particle size, especially 10 μm.
It is preferable that it is below. Further, when used as a magnetic material or a semiconductor material, it is preferable to have high purity since contamination with impurities is avoided. Examples of compounds whose starting materials yield metal oxides by heating include hydroxides, carbonates, and nitrates of the respective metals. The raw materials are thoroughly mixed as they are or together with alcohols, acetone, etc. The mixing ratio of the raw materials needs to be such that the ratio of In, Fe, and Zn is 1:1:5 in atomic ratio. If this is removed, a single phase of the target compound cannot be obtained. This mixture is stored in the air, in an oxidizing atmosphere, or
650℃ in a reducing atmosphere where In and Fe are not reduced from trivalent ion state and Zn from divalent ion state.
Heat above. Heating time is several hours or more. There are no restrictions on the rate of temperature increase during heating. After heating, it can be rapidly cooled, or it can be rapidly drawn out into the atmosphere. The obtained InFeZn ₅ O ₈ compound powder was brown in color and was found to have a crystalline structure by powder X-ray diffraction. Its crystal structure is layered,
It was found that it was formed by stacking _1.5 layers of InO, _2.5 layers of (Fe, Zn)O, and a layer of ZnO. Example: Indium oxide (In ₂ O ₃ ) powder with a purity of 99.99% or more, iron oxide (Fe ₂ O ₃ ) powder with a purity of 99.9% or more, and reagent grade zinc oxide (ZnO) powder in a 1:1 molar ratio. Ethanol was added to the mixture in an agate mortar and mixed for about 30 minutes to obtain a fine powder mixture with an average particle size of several μm. The mixture was sealed in a platinum tube, placed in a tubular siliconite furnace set at 1450°C, and heated for 3 days, and then the sample was taken out of the furnace and rapidly cooled to room temperature. The obtained sample is _a single phase of _InFeZn5O8 ,
The results of measuring each plane index (hkl), plane spacing (d _p ), and relative reflection intensity by powder X-ray diffraction method are shown in Table-
It was as follows. The lattice constants as a hexagonal crystal system were a=3.288±0.001 (Å) and c=57.28±0.01 (Å). The above lattice constants and the surface index (hkl) in Table 2
The calculated interplanar spacing (d _c (Å)) matches the actually measured interplanar spacing (d _p (Å)) extremely well. Effects of the Invention The present invention provides novel compounds useful as magnetic materials, semiconductor materials, and catalysts.

Claims (1)

[Claims] 1. A compound having a hexagonal layered structure represented by InFeZn ₅ O ₈ . 2 Metallic indium or indium oxide or a compound that decomposes into indium oxide when heated; Metallic iron or iron oxide or a compound that decomposes into iron oxide when heated; Metallic zinc or zinc oxide or a compound that decomposes into zinc oxide when heated. and In, Fe, and Zn in an atomic ratio of 1:1:5, and the mixture was heated at 650°C.
In the air, in an oxidizing atmosphere, or at temperatures above
A method for producing a compound having a hexagonal layered structure represented by InFeZn ₅ O ₈ , which is heated in a reducing atmosphere in which In and Fe are not reduced to a trivalent ion state, and Zn is not reduced to a divalent ion state.