Synchrotron X-ray diffraction study of ErMn_2D_2

摘要

ErMn_2D_2 deuteride has been studied by high-resolution synchrotron X-ray powder diffraction at temperatures between 150 and 298 K. Below 210 K a transformation from the hexagonal C14 Laves phase type structure (space group P6_3/mmc; a = 5.55357(3) A; c = 9.05368(7) A; T = 298 K) into the monoclinic one crystallising in the space group C2/m (a = 9.61247(9) A; b = 5.57558(4) A; c = 9.07102(8) A; beta = 90.5451(5) deg; T = 150 K) takes place. A rather large two-phase region of coexistence of both structural modifications was observed between 185 and 205 K.