Polarized neutron investigation in the mixed-valence compound Sm3Te4

Cubic Sm3Te4 can be characterized as a semiconducting, inhomogeneous mixed-valence system. No evidence of charge ordering is found at low temperature, indicating that Sm2+ and Sm3+ ions are randomly distributed on one crystallographic position. The magnetization density of a Sm3Te4 single crystal was measured at 1.5 K using polarized neutrons, with a magnetic field applied along [1 (1) over bar 0]. As the Sm3Te4 structure is not centric, the measured flipping ratios have been directly processed by the maximum entropy method and by a least-squares refinement. The two approaches are in agreement: under the action of the magnetic field, the Sm site splits into two subsites, with very different induced magnetization densities. Two possible explanations are proposed. (C) 1999 Elsevier Science B.V. All rights reserved.