Crystal structure of new ternary compounds Al2R11Ge8 (R = Y, Gd, Tb, Dy, Ho, Er) and thermal properties of Al2Er11Ge8
摘要
The crystal structure of new ternary compounds Al2R11Ge8 (R = Y, Gd, Tb, Dy, Ho, Er) was studied using X-ray powder diffraction data by Rietveld method. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) was used for sample composition examination. The compounds crystallized in the Ge10Ho11 structure type (space group I4/mmm). The phase was not found in the systems with R = La, Ce, Pr and Nd. The lattice thermal expansion study of the Al2Er11Ge8 compound was carried out using high-temperature powder X-ray diffraction technique from 293 K to 743 K, and the calculated lattice and volume thermal expansion coefficients were 伪a = 0.88 脳 10鈭? K鈭?, 伪c = 1.22 脳 10鈭? K鈭?, and 伪V = 3.01 脳 10鈭? K鈭?, respectively.