JPS5933537B2 - Compound having hexagonal layered structure represented by TmGaMnO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound TmGaMn04 having a hexagonal layered structure and a method for producing the same.

Conventionally, compounds having a hexagonal layered structure represented by YFe2O4 are 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 provides a novel compound in which Tm3+ is substituted for Y3+, Mn2+ is substituted for Fe2+, and Ga3+ is substituted for Fe3+ in the compound Y゜+Fe゛+Fe'+OH-, and a method for producing the same. In the compound represented by TmGaMn04 of the present invention, thulium exists as a Tm3+ ion, manganese exists as Mn2+, and gallium exists as a trivalent ion, and can be expressed as Tm3+Ga2+Mn2+01-. This crystal has a hexagonal layered structure as shown in FIG. The largest circle indicates oxygen, the middle circle indicates thulium, and the smallest black circle indicates Ga and Mn. Ga and Mn
is entered randomly. Divalent ions of manganese and Ga
The trivalent ions are surrounded by five-coordinated oxygen ions and occupy the same crystallographic positions. Moreover, Tm has six-coordinated oxygen around it. Oxygen, an anion, has a dense structure. The plane index (hkl) of this crystal,
Surface spacing (dλ) (do- indicates actual measurement, dc indicates calculated value)
The relative reflection intensity (I%) for X-rays is shown in Table 1.

The space group is R3m, the crystal habit is plate-like, and the lattice constant is as follows. ao-3.4564±0.000
1(A)c0=25.690±O, 002(Λ)Table 1 TmGaMn04 This compound is useful as a catalyst material as well as a semiconductor material.

This compound can be produced by the following method.

Thulium oxide (Tm2O3), manganese oxide (Mn
O) and gallium oxide (Ga2O3) in a molar ratio of approximately 1:2:1, and heating the mixture at a temperature of 900°C or higher in a non-oxidizing atmosphere. can. As for the thulium oxide used in the present invention, commercially available products may be used as they are, but in order for the reaction between the oxides to proceed quickly, the smaller the particle size, the better.
In particular, it is 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 of ordinary reagent grade level may be used. The particle size is preferably 10 pm or less for the same reason as for thulium oxide. Preferably, the material is calcined in a mixed gas of carbon dioxide and hydrogen (mixing ratio: 1:1 by volume) at 1000° C. for one day, and then rapidly cooled to 0° C., since the reaction speeds up. The gallium oxide may be of special reagent grade. As mentioned above, the particle size is preferably 10 μm or less. Also, 1 at 800℃
Preferably, the material is calcined in air for several days. These raw materials are thoroughly mixed as they are or with alcohol, acetone, etc. added. These mixing ratios are Tm2O3, MnO.
The molar ratio of Ga2O3 is 1:2:1. If this ratio is exceeded, the desired layered compound cannot be obtained. These mixtures are sealed in a quartz or platinum 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 be oxidized and become trivalent, so it is necessary to be in a non-oxidizing atmosphere. The heating temperature may be 900°C or higher, and the heating time is 10 minutes or more, preferably 1 hour 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 TmGaMnO4 compound has a black metallic luster and is powder X.
It was found by line diffraction that it has a crystalline structure.

The valence of manganese ions in the compound was determined by gravimetric analysis, which measures the change in weight of the sample when it is heated in air. Examples Thulium oxide (Tm2O3) powder with a purity of 99.9% or more, manganese oxide (MnO) powder with a purity of 99.9% or more, and gallium oxide (Ga2O) with a purity of 99.9% or more
3) Powders were weighed at a molar ratio of 1:2:1, and acetone was added in a mortar and thoroughly mixed to obtain a fine powder mixture with an average particle size of several μm.

The mixture was placed in a platinum tube (inner diameter 8 mm) and sealed by electric welding. This was placed in a box-shaped siliconite furnace set at 1000'C and heated for about 4 days, after which the sample was removed and rapidly cooled to room temperature. The result is T
It was a hexagonal layered compound of mGaMnO4. The properties of the crystal were as shown in Table 1.

[Brief explanation of the drawing]

The drawing is a diagram of a TmGaMnO4 crystal of the present invention.

Claims (1)

[Scope of Claims] 1 A compound having a hexagonal layered structure represented by TmGaMnO_4. 2 Thulium oxide (Tm_2O_3), manganese oxide (MnO) and gallium oxide (Ga_2O_3) are mixed in a molar ratio of approximately 1:2:1, and this mixture is heated at 900°C or higher in a non-oxidizing atmosphere. A method for producing a compound having a hexagonal layered structure represented by TmGaMnO_4, which comprises heating at a certain temperature.