Physical Properties of RSe2−x (R=Ce, Nd, Sm and Gd) and RbxGdSe3−y Original Research Article

The physical properties of the rare-earth metal diselenides RSe2−x and rubidium intercalated gadolinium triselenide RbxGdSe3−y were investigated. The resistivity and the electron diffraction scattering measurements of RSe2−x revealed that the energy gaps of these semiconductive compounds are related to the presence of the superstructures due to distortion of the Se-layer. All magnetic RSe2 and RbxGdSe3−y show antiferromagnetic transition. The anisotropy of the magnetic moment in RSe2−x and RbxGdSe3−y originates in the single ion anisotropy of the rare-earth metal while the direction of magnetic moment in the ordered state originates also in the single ion anisotropy in the case of RSe2−x but in the dipolar interaction in RbxGdSe3−y.