Magnetic measurements on ytterbium selenate octahydrate and the nature of its ligand field

Abstract

The principal magnetic susceptibilities of the single crystal of ytterbium selenate octahydrate have been measured in the temperature range 90–300 K. A least squares fit of the Curie–Weiss law to χ̄ yields a negative paramagnetic Curie temperature, similar to an antiferromagnetic material. The site symmetry of the RE3+ ions in sulfates and selenates is discussed. A fairly good explanation of the observed data is obtained through an analysis with a crystal field (CF) of tetragonal symmetry. Some interesting thermal and hyperfine properties are also predicted. From the structural and magnetic studies of RE sulfates and selenates it is concluded that the CF in these salts is of tetragonal symmetry at least to the first approximation.