JPH0435419B2 - - 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 LuFeZn 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 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,
The object of the present invention is to provide a novel compound obtained by replacing Yb ³⁺ with Lu ³⁺ and Fe ²⁺ with Zn ²⁺ , corresponding to n=1/9. Structure of the Invention In the ionic crystal model, the compound represented by LuFeZn ₉ O ₁₂ of the present invention is Lu ³⁺ (Fe ³⁺ Zn ²⁺ )Zn ₈ ²⁺ O ₁₂
^2- , its structure is LuO _1.5 layer, (Fe,
It is formed by laminating a 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 together with Fe ³⁺ form the (Fe ³⁺ Zn ²⁺ )O _2.5 layer, and the remaining 8/9 form the ZnO layer. The lattice constants as a hexagonal crystal system are as follows. a=3.297±0.001 (Å) c=87.84±0.01 (Å) Planar index (hkl), plane spacing (d (Å)) of this compound
(d _p is an actual measurement 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.

【table】

【table】

[Table] This compound can be produced by the following method. Metallic lutetium or lutetium oxide or a compound that is decomposed into lutetium 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. , the proportion of Lu, Fe and Zn is 1 in atomic ratio
The mixture is mixed at a ratio of 1:9, and the mixture is heated at a temperature of 700°C or higher in air, an oxidizing atmosphere, or Lu
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 is or together with alcohols, acetone, etc. The mixing ratio of the raw materials needs to be such that the ratio of Lu, Fe, and Zn is 1:1:9 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
Lu and Fe are each in a trivalent ion state, and Zn is each in a 2-valent state.
In a reducing atmosphere that does not reduce from the valent ion state
Heat over 700℃. 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 LuFeZn 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 LuO, _2.5 layers of (Fe, Zn)O, and a layer of ZnO. Example Lutetium oxide (Lu ₂ O ₃ ) with a purity of 99.99% or more
Powder, iron oxide (Fe ₂ O ₃ ) powder with a purity of 99.9% or more,
Weigh out reagent-grade zinc oxide (ZnO) powder at a molar ratio of 1:1:14, add ethanol in an agate mortar, and mix for about 30 minutes to obtain a fine powder mixture with an average particle size of several μm. Ta. The mixture was sealed in a platinum tube, placed in a tubular siliconite furnace set at 1450°C, and heated for 7 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 LuFeZn ₉ O ₁₂ ,
Table 2 shows the results of measuring each plane index (hkl), plane spacing ( _dp ), and relative reflection intensity by powder X-ray diffraction. The lattice constants as a hexagonal crystal system were a=3.297±0.001 (Å) and c=87.84±0.01 (Å). The above lattice constants and the surface index (hkl) in Table 2
The calculated interplanar spacing (d _c (Å)) was 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 LuFeZn ₉ O ₁₂ . 2 Metallic lutetium or lutetium oxide or a compound that is decomposed into lutetium oxide by heating; Metallic iron or iron oxide or a compound that is decomposed into iron oxide by heating; and Metallic zinc or zinc oxide or a compound that is decomposed into zinc oxide by heating. and Lu, Fe, and Zn in an atomic ratio of 1:1:9, and the mixture is exposed to air, oxidizing atmosphere, or Lu at a temperature of 700°C or higher.
A method for producing a compound having a hexagonal layered structure represented by LuFeZn 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.