JPS5943422B2 - Compound having hexagonal layered structure represented by ErFeMgO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound ErFeMgO4 having a hexagonal layered structure and a method for producing the same.

Conventionally, a compound having a hexagonal layered structure represented by YFe204 was synthesized by the present applicants and its existence is already known.

In this compound, as shown by Y_3+Fe2+Fe_3+042-, divalent ions and trivalent iron ions are 5
Yttrium (Y) surrounded by coordinating oxygen ions
is a compound that has six-coordinated oxygen ions around it, and is magnetic. The present invention provides the above Y_3+
The object of the present invention is to provide a novel compound in which Y_3 of a Fe2+Fe_3+042- compound is replaced with Er_3+ and Mg2+ is replaced with Fe2+, and a method for producing the same.

In the compound represented by ErFeMg04 of the present invention, iron is Fe_3+ ion and erbium is Er
_3+ Magunium exists as Mg2+, and E
It can be expressed as r_3+Fe_3+Mg2+042-.

This crystal has a hexagonal layered structure as shown in FIG. The largest circle indicates oxygen, the middle circle indicates erbium, and the smallest black circle indicates Fe and Mg. Fe and Mg are randomly distributed. The divalent ions of magnesium and the trivalent ions of iron are surrounded by five-coordinated oxygen ions.
Crystallographically, they occupy the same position. Also, Er has six-coordinated oxygen atoms around it. Oxygen, an anion, has a dense structure. s, and u indicate the position within the unit cell. The plane index (hkl) of this crystal,
Surface spacing (d(A)) [do is actually measured, dc is calculated value.

], the relative reflection intensity I (equity) for X-rays is as shown in Table 1. Er(FeMg)04doCλ] dcC included] Ic%] 8.5578.56265 4.2884.28151 _3.029_3.028100 2.8552.85474 The space group is R7m, the crystal habit is plate crystal, The lattice constants are as follows.

〜νυ−1− This compound &; is useful as a magnetic material, a semiconductor material, and a catalyst.

This compound can be produced by the following method.

Metallic erbium (Er) or erbium oxide (Er)
2O3) or a compound that decomposes into erbium oxide (Er2O3) 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 erbium, iron, and magnesium in an atomic ratio of 1:1:1. They can be produced by heating in a reducing atmosphere that does not reduce the trivalent ion state or the divalent ion state, respectively.

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.

Furthermore, when used as a magnetic material or an electric material, the higher the purity of the starting material, the better, since contamination with impurities is to be avoided. 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 erbium, iron, and magnesium is 1:1:1.

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 under an oxidizing atmosphere or a reducing atmosphere such that iron and magnonium 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 ErFeMgO
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. Example: Erbium oxide (Er2O3 purity 99.9f) or higher
) powder, purity 99.9 (iron oxide (Fe2O3
) powder, and reagent grade magnesium oxide (MgO)
The powder 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 ErFeMgO4, 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 a diagram of an ErFeMgO2 crystal of the present invention.

Claims (1)

[Claims] 1. A compound having a hexagonal layered structure represented by ErFeMgO_4. 2 Erbium metal (Er) or erbium oxide (
Er_2O_3) or a compound that decomposes into erbium oxide (Er_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, and magnesium. (Mg) or magnesium oxide (MgO), or a compound that decomposes to produce magnesium oxide (MgO) when heated, so that the ratio of erbium, iron, and magnesium is 1:1:1 in atomic ratio. ErFeMgO_4 is mixed and heated 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