Stabilization by a Divalent Transition Metal in Lead Indium Quaternary Selenide, Fe_0.47Pb_8.04In_17.37Se₃₄, and Specific Indium Coordination

Single crystals of the first M−Pb−In−Se quaternary selenide, Fe0.47Pb8.04In17.37Se34, with the structure stabilized by a divalent transition metal (M = Fe), have been grown by a solid-state reaction. The FeII ions partially occupy at the In sites with various Fe/In ratios. Thus, a new crystal structure is evolved by partially occupied minor Fe atoms at In sites. A part of the In atoms shows remarkably distorted octahedral coordination. This compound shows relatively high conductivity (∼40 S/m at 300 K) with a narrow-band-gap-type semiconducting property (Ea = 0.078 eV).本研究通过固相反应（solid-state reaction）法，生长得到了首个由二价过渡金属（M=Fe）稳定晶体结构的M-Pb-In-Se四元硒化物（quaternary selenide）Fe₀.₄₇Pb₈.₀₄In₁₇.₃₇Se₃₄单晶。二价铁离子（FeII）以不同的Fe/In比例部分占据铟晶格位点，因此通过在铟位点部分占据少量铁原子，演化得到全新的晶体结构。部分铟原子呈现出显著畸变的八面体配位环境。该化合物在300 K时的电导率约为40 S/m，表现出窄带隙型半导体特性，其活化能（Ea）为0.078 eV。