JPH0435416B2 - - 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 TmFeZn ₉ O ₁₂ , 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 Conventional (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 = 1/9, Tm ³⁺ instead of Yb ³⁺ ,
The object of the present invention is to provide a novel compound obtained by replacing Fe ²⁺ with Zn ²⁺ . Structure of the Invention In the ionic crystal model, the compound represented by TmFeZn ₉ O ₁₂ of the present invention is Tm ³⁺ (Fe ³⁺ , Zn ²⁺ )Zn ₈ ²⁺
Described as O ₁₂ ^2- , its structure is TmO _1.5 layer,
It is formed by laminating a (Fe,Zn)O _2.5 layer and a ZnO layer, and one of its characteristics is that it has significant structural anisotropy. 1/9 of the Zn ²⁺ ions form a (Fe ³⁺ , Zn ²⁺ )O _2.5 layer with Fe ³⁺ , and the remaining 8/9
Creating a ZnO layer. The lattice constants as a hexagonal crystal system are as follows. a=3.329±0.001(Å) c=87.77±0.01(Å) Planar index (hkl), plane spacing (d(Å)) of this compound
(d _p is the measured value, d _c is the calculated value) and the relative reflection intensity (I (%)) for X-rays is shown in Table 2.
It is as follows. 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 thulium or thulium oxide or a compound that is decomposed into thulium oxide by heating; Metallic iron or iron oxide or a compound that is decomposed into iron oxide by heating; Metallic zinc or zinc oxide or a compound that is decomposed into zinc oxide by heating. are mixed in an atomic ratio of Tm, Fe, and Zn in an atomic ratio of 1:1:9, and the mixture is heated at a temperature of 650°C or higher in the air, in an oxidizing atmosphere, or when Tm and Fe are each trivalent ions. Zn is produced by heating in a reducing atmosphere in which Zn is not reduced from a divalent ion state. 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 is or together with alcohols, acetone, etc. The mixing ratio of the raw materials requires that the ratio of Tm, Fe, and Zn be in an atomic ratio of 1:1:9. 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 Tm and Fe are not reduced from the trivalent ion state and Zn from the 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 TmFeZn ₉ O ₁₂ 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 TmO, _2.5 layers of (Fe, Zn)O, and a layer of ZnO. Example: Thulium oxide (Tm 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. The mixture was weighed at a ratio of 18:1, ethanol was added 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 2 days, after which the sample was taken out of the furnace and rapidly cooled to room temperature. The obtained sample is a single phase of TmFeZn ₉ O ₁₂ ;
Table 2 shows the results of measuring each plane index (hkl), plane spacing (d _p ), and relative reflection intensity using powder X-ray diffraction method.
It was hot on the street. The lattice constants as a hexagonal crystal system were a=3.294±0.001 (Å) and c=87.77±0.01 (Å). The above lattice constants and the surface index (hkl) in Table 2
The calculated interplanar spacing (d _c (Å)) is in extremely good agreement with the actually measured interplanar spacing (d _p (Å)). 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 TmFeZn ₉ O ₁₂ . 2 Metallic thulium or thulium oxide or a compound that is decomposed into thulium oxide by heating,
Metallic iron, iron oxide, or a compound decomposed into iron oxide by heating, and metallic zinc, zinc oxide, or a compound decomposed into zinc oxide by heating, when the ratio of Tm, Fe, and Zn is 1 in atomic ratio.
The mixture is mixed at a ratio of 1:9 to
A method for producing a compound having a hexagonal layered structure represented by TmFeZn ₉ O ₁₂ , which comprises heating in a reducing atmosphere in which Fe is not reduced to a trivalent ion state and Zn is not reduced to a divalent ion state.