新規な層状炭化物ホモロガス相Zr₂Al₄C₅ とZr₃Al₄C₆ の合成と結晶構造解析

抄録

Two types of new ternary carbides, Zr₂Al₄C₅ and Zr₃Al₄C₆, have been synthesized and characterized by X-ray powder diffraction. The crystal structures were refined from laboratory X-ray powder diffraction data (CuKα₁) using the Rietveld method. These carbides form a homologous series with the general formula (ZrC)_mAl₄C₃ (m = 2 and 3). The crystal structures can be regarded as intergrowth structures where the Al₄C₃-type [Al₄C₄] layers are the same, while the NaCl-type [Zr_mC_m+1] layers increase in thickness with increasing m value. The new carbides are most probably the end members of continuous solid solutions (ZrC)_m[Al_4-xSi_x]C₃ with 0 ≤ x ≤ 0.44.