Electron Paramagnetic Resonance Spectrum of Pr4+in Sr2CeO4

The electron paramagnetic resonance (EPR) spectra of Pr4+diluted in Sr2CeO4were measured at 4.2 K. A very large hyperfine interaction with the141Pr nucleus was observed. The spectra were anisotropic, due to the distortion of the octahedral oxygen coordination symmetry around the Pr4+ion. The results were analyzed based on the weak field approximation, and the followinggvalues and hyperfine coupling constantsAwere obtained: g||=1.169, g=0.966, A||=0.0703 cm-1, and A=0.0669 cm-1. The measuredgvalues are smaller than -10/7, showing that the crystal field is effective to some extent on the behavior of a 4felectron in Sr2CeO4.