Synthesis and characterization of Er(3)SmQ(6) (Q = S, Se) and Er1.12SM0.88Se3

摘要

The interlanthanide compounds Er3SmS6, Er3SmSe6, and Er1.12Sm0.88Se3 have been synthesized front stoichiometric reactions of the elements in a KI salt flux at 1273, 1173, and 1123 K, respectively. Er3SmS6 and Er3SmSe6, which are isostructural and ordered, crystallize in space group P2(1)/m in the ScEr3S6 structure type whereas Er1.12Sm0.88Se3, in which the Er and Sm atoms are disordered, crystallizes in space group Pinna in the U2S3 structure type. Er3SmS6 is a paramagnet with a mu,(eff) = 11.25(l) mu(B)/mol. From optical measurements a direct band gap of 2.0 eV for light perpendicular to the (100) crystal face of Er3SmSe6 is derived whereas for isostructural Er3SmS6 an optical transition at 2.2-2.4eV and a broad absorption peak at lower energies are observed. (C) 2007 Elsevier Inc. All rights reserved.