Slowly fluctuating random strains in the excited-state Jahn-Teller system TmPO4

A slight magnetic field dependence in the electron-paramagnetic-resonance fine-structure spectrum of Gd3+ in TmPO4 is observed and explained in terms of slowly fluctuating magnetic-field-induced moments in the dynamic random Jahn-Teller-split excited states of Tm3+. © 1983 The American Physical Society.