Preparation and Characterization of Perovskite-type ternary Sulfides.

Some of the ternary oxides having Perovskite-type structure，ABO_3(A，B：metals)，orrelatcd compounds exhibit interesting electuic，dielectric and/or magnetic properties，e.g.，BaTiO_3，YBa_2Cu_3O_y.However，only a few termary sulfides having Perovskite-type structure have been known，so far although，several interesting possibities，such as cathmater Perovskite-type structure having been known，so far although，several interesting possibities，such as cathmateriasls of typestructure have been known，so far although，several interesting pos.Accordingly，I have tried to prepare Perovskite-type ternary sulfides in this study.In1993，preparatios of LiMnS_3，LiWS_3，LiCrS_3，CuMnS_3，CuWS_3，CuCrS_3Perovskites were carried out using each metal element，Li_2S and sulfur，in evacuated quartz tubes at temperatures of 600-800难民C.However，in each case excess sulfur was left in the quartz tube and perovskites no temperatures in this study.In1993，in each case excess sulfur was left in the quartz tube and perovskites no tawer.Accordingly，in1994，ternary sulfides with lower sulfur compositions were prepared。In the Cu-Cr-S system，CuCr_2S_4spinel was prepared.From this compound，some part of copper ions was rcmoved by a leaching reaction using hydrochloric acid，which could be used as a cathode material of a lithium secondary battery，and the lithium cell showed an energy density of 50Wh/kg。In the Li-Mn-S system，a new compound，which is supposed to be the LiMn_2S_4spinel，was obtained(No Single Phase Was Obtained)。The cathode property of this material is going to be tested.In this system，Li_xMn_&lt；1-x&gt；S with a cubic NaCl type structure was also preparcd。The homogeniety range of this solid solution was found to be0&lt；x&lt；0.27。The lattice parameter of cubic MnS decreased with increasing x value.Also，the specific resistivity of MnS(-10^&lt；-6&gt；OMEGA·cm，20ºC)decreased to-10^&lt；-2&gt；OMEGA·cm for Li_&lt；0.2&gt；Mn_&lt；0.8&gt；.Li_xMn_&lt；1-x&gt；S is also a new compound，and characterizations are going to be carried out。

Some of the ternary oxides having Perovskite-type structure, ABO_3 (A,B : metals), orrelatcd compounds exhibit interesting electuic, dielectric and/or magnetic properties, e.g., BaTiO_3, YBa_2Cu_3O_y. However, only a few termary sulfides having Perovskite-type structure have been known, so far although, several interesting possibitities, such as cathde materiasls of lithium secondary batteries can be expected for these compounds. Accordingly, I have tried to prepare Perovskite-type ternary sulfides in this study.In 1993, preparatios of LiMnS_3, LiWS_3, LiCrS_3, CuMnS_3, CuWS_3, CuCrS_3 Perovskites were carried out using each metal element, Li_2S and sulfur, in evacuated quartz tubes at temperatures of 600-800ﾟC.However, in each case excess sulfur was left in the quartz tube, and no perovskites were obtained. Accordingly, in 1994, ternary sulfides with lower sulfur compositions were prepared. In the Cu-Cr-S system, CuCr_2S_4 spinel was prepared. From this compound, some part of copper ions was rcmoved by a leaching reaction using hydrochloric acid, which could be used as a cathode material of a lithium secondary battery, and the lithium cell showed an energy density of 50 Wh/kg. In the Li-Mn-S system, a new compound, which is supposed to be the LiMn_2S_4 spinel, was obtained(no single phase was obtained). The cathode property of this material is going to be tested. In this system, Li_xMn_<1-x>S with a cubic NaCl type structure was also preparcd. The homogeniety range of this solid solution was found to be 0<x<0.27. The lattice parameter of cubic MnS decreased with increasing x value. Also, the specific resistivity of MnS(-10^<-6>OMEGA ・ cm, 20ﾟC)decreased to -10^<-2>OMEGA ・ cm for Li_<0.2>Mn_<0.8>. Li_xMn_<1-x>S is also a new compound, and characterizations are going to be carried out.