JPH11171545A - Cu2hfs3 and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel compound obtained in a Cu-Hf-S system useful as semiconductor, etc., and its production method. SOLUTION: Metal Cu, Hf, and HfS2 , CuS or S having 2:1:3 Cu:Hf:S atomic ratio are mixed, and mixed powder is compacted to form a green compact and heated at 600-1300 deg.C for more than two days in an evacuated sealed tube to produce a sintered compact being a compound having a trigonal structure shown as Cu2 HfS3 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The invention of this application is based on Cu ₂ H
fS ₃ and a manufacturing method thereof. More specifically, the invention of this application relates to Cu ₂ HfS ₃ which is a novel compound useful as a semiconductor material, a cathode material for a secondary battery, and the like, and a method for producing the same.

[0002]

_2. Description of the Related Art Hitherto, there has been no report on the correlation between ternary compounds in a Cu-Hf-S system except for a cubic spinel phase Cu _x HfS ₂ . Although the Cu-Hf-S ternary compound is expected to have properties as a semiconductor material, a conductive material, and further as a secondary battery positive electrode material, the ternary compound is actually So far little has been considered,
Except for the above-mentioned known examples, no clues have been obtained in the future.

Accordingly, the invention of this application overcomes the limitations of the conventional technical situation and provides a novel compound obtained in a Cu-Hf-S system, which is expected to develop semiconductor materials in the future, and a method for producing the same. It is intended to be.

[0004]

Means for Solving the Problems The present invention provides a compound having a trigonal structure represented by Cu ₂ HfS ₃ (Claim 1) to solve the above problems. In addition, the present invention provides a method for producing a metal Cu, Hf and HfS ₂ ,
uS or S is mixed at an atomic ratio of Cu: Hf: S of substantially 2: 1: 3, and the mixed powder is pressed to form a green compact, which is heated in a vacuum-evacuated sealed tube. Cu ₂ HfS characterized by producing a sintered body by performing
_{A third} manufacturing method (claim 2) is provided.

Further, according to the present invention, the heating temperature is from 600 to 1
Embodiments such as 300 ° C. (Claim 3) and a heating time of 2 days or more (Claim 4) are also provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The compound represented by Cu ₂ HfS _{3 according} to the present invention has a structure in which Hf is located at the 6-coordinate position of the sulfur lattice, and
u is a layered structure material occupying the tetracoordinate and tricoordinate positions at a ratio of 3: 1. The lattice constant of the trigonal system is a = 6.
456 ± 0.001 (Å), c = 12.188 ± 0.0
02 (Å), V = 439.9 ± 0.2 (Å ³ ),
The space group is P31c (No. 163).

In the method for producing the compound represented by Cu ₂ HfS ₃ of the present invention, a commercially available product may be used as a starting material as it is, but when the compound is used as a semiconductor material or a cathode material for a secondary battery. It is desirable to use a starting material having as high a purity as possible without containing impurities. Further, in the process of heat treatment, it is desirable to reduce the particle size of the powder as much as possible to promote the reaction, and to perform these treatments in a closed system in order to avoid oxidation in the air. After the heating is completed, it is appropriate to put the quartz sealed tube in water and rapidly cool it.

Compound C obtained by the method of the present invention
The powder of u ₂ HfS ₃ is black, and the powder and single crystal X
It has been confirmed by a line diffraction method that it has a trigonal crystal structure. The configuration and the features of the operation and effect will be described in more detail with reference to the following embodiments. Of course, the present invention is not limited by the following examples.

[0009]

EXAMPLE A Cu powder having a purity of 99.9% or more and a purity of 99.9% or more were obtained.
7% or more of HfS ₂ powder and 99.9999% or more of S powder are weighed in a glove box so that the atomic ratio of Cu: Hf: S becomes 2: 1: 3, and in an agate mortar. After mixing for 5 minutes, the mixed powder was pressed to form a green compact.

Next, this is vacuum-sealed in a transparent quartz tube,
Heated in a horizontal tubular electric furnace set at 600 ° C for 1 day,
After further heating at 800 ° C. for 2 days, the quartz tube was taken out and quenched in water. Plane index (hkl), plane spacing (d (Å)) (d _o is a measured value, d _o is a calculated value), and powder X-ray diffraction intensity (I) of the obtained Cu ₂ HfS ₃ phase compound
(%)) (I _o is the measured intensity) was measured by the powder X-ray diffraction method. The results are shown in Table 1.

[0011]

The lattice constant of the former trigonal system is a
= 6.456 ± 0.001 (Å), c = 12.188 ±
0.002 (Å), V = 439.9 ± 0.2 (Å ³ ). The plane spacing d (Å) calculated from these lattice constants and each plane index (hkl) shown in Table 1 was extremely consistent with the measured plane spacing (d _o (Å)).

Further, when the electric resistance at room temperature to liquid nitrogen temperature was measured by the four-terminal method, Cu ₂ HfS ₃ , a compound of the present invention, was a semiconductor and exhibited a value of ₂₀ Ω / cm at room temperature.

[0013]

As described above in detail, the present invention provides a novel compound having a trigonal structure represented by Cu ₂ HfS ₃ and a method for producing the same. This Cu ₂ HfS ₃ is useful as a semiconductor material or a cathode material for a secondary battery.

Claims (4)

[Claims] 1. A compound having a trigonal structure represented by Cu ₂ HfS ₃ . 2. Metal Cu and Hf and HfS ₂ , CuS or S, Cu: Hf: S in an atomic ratio of substantially 2: 1: 3.
Were mixed so that the ratio of the green compact powder mixture under pressure, Cu ₂ according to claim 1, characterized in that to produce a sintered body by which the heating in vacuum were sealed tube
Method of manufacturing a HfS _{3. 3.} The method for producing Cu ₂ HfS _{3 according to} claim 2, wherein the heating temperature is 600 to 1300 ° C. 4. The method for producing Cu ₂ HfS _{3 according} to claim 2, wherein the heating time is 2 days or more.