JPS5933538B2 - Compound having a layered structure of hexagonal crystal threads represented by TmAlMnO↓4 and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel compound TmAlMnO4 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+O. The present invention provides a novel compound in which Y3+ is replaced by Tm3+, Fe2+ is replaced by Mn2+ (Fe3+ is replaced by Al3+), and a method for producing the same is provided. In the compound represented by TmAlMnO4 of the present invention, thulium is Tm3+
ions, manganese exists as Mn2+, aluminum exists as trivalent ions5, and Tm3+Al3+Mn2+
01-. This crystal has a hexagonal layered structure as shown in FIG. The largest circle is oxygen, the middle circle is thulium, and the smallest black circle is aluminum and Mn.
shows.

Aluminum and magenta guns are included randomly.
The divalent ion of manganese and the trivalent ion of aluminum are 5
It is surrounded by coordinating oxygen ions and occupies the same crystallographic position. Thulium also has six-coordinated oxygen atoms around it. Oxygen, which is an anion, has a dense 15-pack structure. The plane index (hkl) of this crystal, the plane spacing (
dλ) (do is an actual measurement, dc is a calculated value), and the relative reflection intensity (I%) for X-rays is as shown in Table 1.

The space group is R, m, the crystal habit is plate-like, and the 20 lattice constant is as follows. a0=3.4590±0.0
004(A)c0=24.912±O, 004(λ)2
5 Table 1 TmAlMn04 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 aluminum oxide (Al2O3) in a molar ratio of about 1:2:1, and heating the mixture at a temperature of 1300 ° 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 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 of ordinary reagent grade level may be used.

The particle size is preferably 10 μm or less for the same reason as the thulium oxide. 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 one day, and then rapidly cool to 0° C., because the reaction speeds up. The aluminum oxide may be of special reagent grade. As mentioned above, the particle size is preferably 10 μm or less. Moreover, it is preferable to calcined it in air at 1000° C. for one day. These raw materials are thoroughly mixed as they are or with alcohol, acetone, etc. added. These mixing ratios are Tm2O3, MnO, . Al2O3 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 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 should be 1300°C or less (・o 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 TmAlMnO4 compound had a black metallic luster and was found to have a crystalline structure by powder X-ray diffraction.

It was found that its structure was the same as that of YFe2O4 already obtained by the applicant. The sample weights of the starting mixed sample and the reaction product were precisely weighed, and the stoichiometry of the resulting sample was determined. 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 a purity of 99.

Aluminum oxide (Al2O3) powder of 9% or more was weighed at a molar ratio of 1:2:1, and acetone was added in a mortar and mixed thoroughly 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.
This was placed in a box-shaped siliconite furnace set at 1500'C and heated for about 3 days, after which the sample was removed and rapidly cooled to room temperature. What was obtained was a hexagonal layered compound of TmAlMnO4. The properties of the crystal are the first
It was as shown in the table.

[Brief explanation of drawings]

The drawing is a diagram of a TmAlMnO4 crystal of the present invention.

Claims (1)

[Claims] 1 A compound having a hexagonal layered structure represented by TmAlMnO_4. 2 Thulium oxide (Tm_2O_3), manganese oxide (MnO) and alumina (Al_2O_3) are mixed at a molar ratio of approximately 1:2:1, and this mixture is heated at a temperature of 1300°C or higher in a non-oxidizing atmosphere. 1. A method for producing a compound having a hexagonal layered structure represented by TmAlMnO_4, the method comprising heating at .