JPS5943419B2 - Compound having hexagonal layered structure represented by LuFeMgO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound, LuFeMg04, 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. Yes, it has magnetism. The present invention provides the above-mentioned Y゜+
The object of the present invention is to provide a novel compound in which Lu_3+ is replaced with Y_3+ and Mg_2+ is replaced with Fe_2+ in a compound of Fe"+Fe°+00", and a method for producing the same.

In the compound represented by LuFeMg04 of the present invention, iron is Fe_3+ ion and lutetium is Lu_3+ ion.
+, magnesium exists as Mg_2+ and can be expressed as Lu_3+Fe_3+M total 04_2-.

This crystal has a hexagonal layered structure as shown in FIG. The largest circle indicates oxygen, the middle circle indicates lutetium, and the smallest black circle indicates Fe and Mg. Fe and Mg are randomly distributed. Divalent ions of magnesium and iron
Trivalent ions are surrounded by five-coordinated oxygen ions. Crystallographically, they occupy the same position. Lutetium also has six-coordinated oxygen atoms around it. Oxygen, an anion, has a dense structure. s, and u indicate the position in the ≠ lattice. Planar index (hkl), interplanar spacing (d(A)) of this crystal [do is actual measurement, dc
indicates a calculated value.

], the relative reflection intensity I (to) for X-rays is as shown in Table 1. Lu(FeMg)04 do[A] dcCA] IC%] 8.4668.4_3668 4. _2_254. _21876_2.951_2.9
The 4879 space group is R3nl, its crystal habit is plate-like, and its 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.

Lutetium metal (Lu) or lutetium oxide (LU
2O3) or a compound that decomposes into lutetium oxide (LU2O3) when heated, and metallic iron, or iron oxide (Fe2O3), or a compound that decomposes into iron oxide (Fe2O3) when heated. Magnesium or magnesium oxide (MgO) or decomposed by heating to produce magnesium oxide (MgO)
gO) in an atomic ratio of lutetium, iron, and magnesium in an atomic ratio of 1:1:1. are respectively 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 it is below m.

Further, when used as a magnetic material or an electric material, since contamination with impurities is to be avoided, the higher the purity of the starting material, the better. This raw material is thoroughly mixed as is or with alcohol or acetone. The mixing ratio of these is 1:1:1 in terms of atomic ratio of lutetium, iron, and magnesium.

If this ratio is exceeded, the target compound cannot be obtained. This mixture is heated at a temperature of 1200° C. or higher in air or in an oxidizing atmosphere or in a reducing atmosphere such that iron and magnesium cannot be reduced from their trivalent and divalent ionic states. Heating time is 1
days 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 LuFeMgO
The four compounds showed a brown color, and by powder X-ray diffraction method,
It was found that it has a crystal structure. It was found that its crystal structure was the same as that of YFe2O4, which had already been obtained by the applicant.

Precisely weigh the sample weights of the starting mixed sample and reaction product,
The stoichiometric number of the obtained sample was determined. Examples Lutetium oxide (to Lu2) powder with a purity of 99.9% or more, iron oxide (Fe2O3) powder with a purity of 99.9% or more,
and reagent grade magnesium oxide (MgO) powder,
The mixture was weighed at a molar ratio of 1:1:1, and ethyl alcohol was added and thoroughly mixed in a mortar to obtain a fine powder with an average particle size of several μm.

The mixture was placed in a platinum crucible, placed in a box-shaped siliconite furnace set at 1400°C, and heated for 3 days.
Thereafter, the sample was taken out of the furnace and rapidly cooled to room temperature. The obtained sample was LuFeMgO4, 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 the drawing]

The drawing is an illustration of a LuFeMgO4 crystal of the present invention.

Claims (1)

[Claims] 1. A compound having a hexagonal layered structure represented by LuFeMgO_4. 2 Lutetium metal (Lu) or lutetium oxide (
LU_2O_3) or a compound that decomposes into lutetium oxide (Lu_2O_3) when heated; metallic iron (Fe) or iron oxide (Fe_2O_3); or a compound that decomposes into iron oxide (Fe_2O_3) when heated; Magnesium (Mg), magnesium oxide (MgO), or a compound that is decomposed to produce magnesium oxide (MgO) when heated, so that the atomic ratio of lutetium, iron, and magnesium is 1:1:1. The method is characterized by heating at a temperature of 1200° C. or higher in the air in an oxidizing atmosphere or in a reducing atmosphere to the extent that iron and magnesium are not reduced to a trivalent ion state or a divalent ion state, respectively. A method for producing a compound having a hexagonal layered structure represented by LuFeMgO_4.