Paramagnetic Resonance in an Excited State of TmN: Crystal-Field and Exchange Effects

Abstract

Paramagnetic resonance has been observed in an excited ${\ensuremath{\Gamma}}_{5}$ triplet state 222\ifmmode^\circ\else\textdegree\fi{}K above the singlet ${\ensuremath{\Gamma}}_{1}$ ground state of ${\mathrm{Tm}}^{3+}$ ($4{f}^{12}$) in TmN (NaCl structure). Much of the observed behavior is understood with exchange small compared with crystal-field effects; however, there is an anomalous minimum in the temperature variation of the resonant $g$.