PARAMAGNETIC-RESONANCE STUDIES OF RARE-EARTH IMPUTITIES IN 2-6 COMPOUNDS

An electron-paramagnetic-resonance study of rare-earth impurities in II-VI compounds has been made. Isolated trivalent rare-earth ions are found to be substitutional for the metal ion in the zinc-blende crystals. Spectra from trivalent ions both at the isolated substitutional site and incorporated in additional unknown ways are observed in the wurtzite crystals. Shifts in the g factor are noted to depend on host covalency in the case of isolated substitutional Yb3+. Yb3+-(noble metal) 1+ associates are studied in CdTe. Observation of ligand hyperfine structure shows that, in this instance, the rare earth is interstitial. Generally, the results indicate that the point-charge model may be usefully applied to determine the mechanism of rare-earth incorporation in II-VI compounds from observation of their paramagnetic-resonance spectra. © 1968 The American Physical Society.