Syntheses, Structures, and Thermal Expansion of Germanium Pyrophosphates

Electron paramagnetic resonance (EPR) spectra of tetravalent praseodymium ions doped in the cubic perovskite compound BaHfO3 have been measured at 4.2 K. A very large hyperfine interaction with the 141Pr nucleus was observed in the spectrum of Pr4+/BaHfO3. The results were analyzed based on the weak field approximation, and the g value (g=0.619) and a hyperfine coupling constant (A=0.0589 cm-1) were obtained. The measured g value is much smaller than - , which indicates that the crystal field effect on the behavior of a 4f electron is large. These g and A values were compared with the EPR results for other f1 ions in an octahedral crystal field.