JPS5933535B2 - Compound having hexagonal layered structure represented by YbGaMnO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound YbGaMnO4 having a hexagonal layered structure and a method for producing the same.

Conventionally, a compound having a hexagonal layered structure represented by YFe204 is known.

This compound is a compound in which divalent and trivalent iron ions are surrounded by five-coordinated oxygen ions, and Y has six-coordinated oxygen ions around it, as shown by Y3+Fe2+Fe3+01~. It has magnetism. The present invention uses Yb3+ in place of Y3+ in the Y3+Fe2+Fe3+01- compound, Mn2+ in place of Fe2+, Fe3
The object of the present invention is to provide a novel compound in which + is replaced with Ga3+, and a method for producing the same. YbGaMnO of the present invention
In the compound represented by 4, ytterbium is a Yb3+ ion, manganese is a Mn2+ ion, and gallium is a 3+ ion.
Exists as valence ions, Yb3+Ga3+Mn2
It can be expressed as +01-.

This crystal has a hexagonal layered structure as shown in FIG. The largest circle is oxygen, the middle circle is Yb, and the smallest black circle is Ga.
and Mn.

Ga and Mn are entered randomly. The divalent ions of manganese and the trivalent ions of Ga are surrounded by five-coordinated oxygen ions and occupy the same position crystallographically. Also Y
b has six-coordinated oxygen around it. Oxygen, an anion, has a dense structure. s, and u indicate the position within the unit cell. Both indices of this crystal (hk
Table 1 shows the relative reflection intensity (I%) for X-rays.

The space group is R3m, the crystal habit is plate-like, and the lattice constant is as follows. ao ■ 3.4437±O, 0O
02 (λ) c0 = 25.709 ± O, 003 (Λ) 1st
Table YbGaMn04 This compound is useful as a catalyst material as well as a semiconductor material.

This compound can be produced by the following method.

Ytterbium oxide (Yb2O3), manganese oxide (MnO) and gallium oxide (Ga2O3) are mixed in a molar ratio of approximately 1:2:1, and the mixture is heated at 700°C or higher in a non-oxidizing atmosphere. It can be produced by heating at a certain temperature. Commercially available ytterbium oxides used in the present invention may be used as they are, but in order to speed up the reaction between the oxides, the smaller the particle size, the better, particularly preferably 10 μm or less.
When used as a semiconductor material, since contamination with impurities is to be avoided, the raw material should preferably be of high purity and should have been calcined in air at about 1000° C. for several hours. Manganese oxide can be used as a normal reagent.

The particle size is 10μ for the same reason as the ytterbium oxide.
It is preferable that it is below m. Further, it is preferable to calcinate in a mixed gas of carbon dioxide and hydrogen (mixture ratio: 1:1 by volume) at 1000° C. for 1 day, and then rapidly cool to 0° C., because the reaction speeds up. The gallium oxide may be of special reagent grade.
The particle size is preferably 10 ttm or less as described above. Moreover, it is preferable to calcined in air at 800° C. for one day. These raw materials are thoroughly mixed as they are or with alcohol, acetone, etc. added. These mixing ratios are Yb2O3, MnO. Ga2O3 molar ratio 1:2
The ratio is 1:1. If this ratio is exceeded, the desired layered compound cannot be obtained. These mixtures are sealed in a quartz or glass container and heated under a non-oxidizing atmosphere.

Since manganese is in a divalent state, in an oxidizing atmosphere (for example, in the atmosphere), manganese will oxidize and become trivalent, so it is necessary to be in a non-oxidizing atmosphere. The heating temperature may be 700° C. or more, and the heating time is 10 minutes or more, preferably 1 hour or more. There is no limit to 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 YbGaMnO4 compound had a black color and was found to have a crystalline structure by powder X-ray diffraction.

The weight of the sample was precisely weighed before and after heating, and it was confirmed that there was no change within the experimental error range, and the stoichiometric number was determined. Examples Ytterbium oxide (Yb2O) with a purity of 99.9% or more
3) Powder, manganese oxide (MnO) with a purity of 99.9% or more
) powder and gallium oxide (G
a2O3) powder in a molar ratio of 1:2:1,
Add acetone in a mortar and mix thoroughly until the average particle size is several μm.
A fine powder mixture was obtained.

The mixture was placed in a transparent quartz tube (inner diameter 8 m TIL), and the inside of the tube was lowered to 10 −3 mL Hgq vacuum using a vacuum pump, maintained for about 1 hour, and then sealed using a gas burner. This was placed in a box-shaped siliconite furnace set at 1000°C and heated for about 5 days, after which the sample was taken out and rapidly cooled to room temperature. What was obtained was a hexagonal layered compound of YbGaMnO4. The properties of the crystal were as shown in Table 1.

[Brief explanation of the drawing]

The drawing is a diagram of the YbGaMnO4 crystal of the present invention.

Claims (1)

[Scope of Claims] 1 A compound having a hexagonal layered structure represented by YbGaMnO_4. 2 Ytterbium oxide (Yb_2O_3), manganese oxide (MnO) and gallium oxide (Ga_2O
A hexagonal layered structure represented by YbGaMnO_4, characterized in that _3) are mixed at a molar ratio of approximately 1:2:1, and this mixture is heated at a temperature of 700°C or higher in a non-oxidizing atmosphere. A method for producing a compound having