COMPOUNDS OF RARE EARTH METALS WITH ELEMENTS OF NITROGEN SUB-GROUP

The possible types of compounds between rare earth metals and the elements of the nitrogen sub-group, referred to as pnictides are considered. The pnictides of the composition LnPn or 1:1 have been most completely studied. These rare earth compounds with the pnictogens are expected to have semiconducting or semimetallic properties because of their electronic structure. The synthesis of pnictides is carried out directly from elements or indirectly through their compounds. The preparation of single crystals of refractory compounds is possible through a gas phase reaction including the use of some substances as transporters. The single crystals of lower-melting compounds (antimonides, bismuthides) are grown from a melt by direct fractional crystallization. No complete investigations of the systems, rare earth metal--nitrogen and rare earth metal--phosphorus have been carried out. the data obtained here are compared to those known for actinide compounds. All known electrical properties of monopnictides of rare earth metals are given. © 1969.