화학공학소재연구정보센터
Materials Research Bulletin, Vol.29, No.5, 567-574, 1994
Recent Progress in Chevrel-Phase Syntheses - A New Low-Temperature Synthesis of the Superconducting Lead Compound
This paper reviews recent progress in the synthesis of Chevrel phases. The objective was to produce better microscopic homogeneity of the elements and/or precursors required to form the phase. Among these new processes, the one dealing with insertion of lead into the binary Mo6S8 compound is particularly attractive for the development of Chevrel phase wire since the phase formation occurs at temperature as low as 440-degrees-C. To achieve good microscopic homogeneity of PbMo6S8 (PMS), PbS is used and the extra sulfur is removed under a hydrogen gas flow. Basic superconducting properties, like a.c. susceptibility transition and specific heat anomaly at T(c), demonstrate extremely fine superconducting particles. Further annealing at the moderate temperature of 600-degrees-C improves the homogeneity and/or the crystallinity of the powder.