X-Ray, infrared, and magnetic studies of α- and β-ruthenium trichloride

摘要: Physical measurements have been made on samples of α- and β-RuCl3 relatively high purity. From X-ray powder patterns, the existence a superstructure has detected in α-RuCl3, structure found to be β-TiCl3 type with linear chains ruthenium atoms lying distorted octahedra chlorine atoms. The infrared spectra obtained down 70 cm.–1; nine bands observed for indicate that space group is trigonal P3c1 (C33v), which means there are–RuCl3–RuCl3–RuCl3–units chains. There strong band attributed Ru–Cl stretching vibration at frequency 376 cm.–1. magnetic susceptibilities, from 8 740°K 560°K β-RuCl3, show α-RuCl3 antiferromagnetic below 13°K, ca. 600°K, but neither case antiferromagnetism by neutron diffraction. temperature dependence susceptibilities compared predictions crystal field theory Heisenberg β-RuCl3.