Research Abstract |
The formation behaviors of R2S3(R:La,Pr,Nd and Sm) powders in sulfurization of La203,Pr6011,Nd203 and Sm203 powders, respectively, using CS2 gas were examined. In all cases, R202S which were intermediate products, were formed in the initial stage of reaction, and R2S3 were formed for a shorter period of time at higher temperature instead of R202S. In the Synthesis of La2S3 and Sm2S3, single-phase、β-La2S3 and α-Sm2S3, respectively, were finally prepared. On the other hand, in the synthesis of Pr2S3 and Nd2S3, α-Pr2S3 and α-Pr2S3 having trace of residual β-Pr2S3 and single β-Pr2S3, respectively, were finally prepared. In all cases, the impurity contents of oxygen and carbon in reaction products were dependent on the sulfurization conditions. In finally experiment, the thermo-electric properties for all rare earth sulfides synthesized were measured. As a result, Zeebeck coefficient and the thermo-electric property for lanthanam sulfide were extremely better than other sulfides.
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