Lattice dynamics and crystal field interactions in lutetium and ytterbium orthovanadates and orthophosphates

Rare-earth orthophosphates (REPO;An understanding of the crystal field in these compounds is central to the theoretical interpretation of interactions with the rare-earth ions. We have measured the magnetic excitation spectra of polycrystalline samples of YbPO;Magnetic ion-lattice interactions are manifested in many of the thermodynamic properties of rare-earth orthophosphates and orthovanadates. Evidence of crystal-field-phonon interactions in YbPO;LuPO...