SPONTANEOUS MAGNETIZATION IN A MIXED-VALENT RARE-EARTH COMPOUND

Clear experimental evidence is given for the first observation of a spontaneous magnetization in a mixed-valent rare-earth compound at low temperatures. The magnetic susceptibility, the magnetization, the magnetostriction, and the electrical conductivity of TmSe0.83Te0.17 reveal a transition to a magnetically ordered state with a net magnetic moment below 5.5 K. This is in quantitative agreement with Varma's recent predictions based on a microscopic model for mixed-valent systems. © 1979 The American Physical Society.