TEMPERATURE-DEPENDENCE OF THE HYPERFINE INTERACTION IN THE CUBIC PHASE OF BAHFO3

[摘要] The temperature dependence of the hyperfine interaction in the paraelectric phase of BaHfO3 in the temperature range from liquid-nitrogen temperature to 1350 K has been studied. The experimental results show an Abragam-Pound mechanism for the attenuation of the angular correlation. In this cubic structure the attenuation would be consistent with a relaxation mechanism that involves O-ion hopping between vacant sites in the lattice. Using the point-charge model for the estimation of the electric field gradient produced by an O vacancy in the coordination sphere of the probe ion, the process is characterized by a correlation time tau-c = 12 +/- 1 ps at RT.