Hyperfine Characterization of SrTixHf1-xO3

R. E. ALONSO, M. FALABELLA AND A. R. LÓPEZ GARCÍA

La Plata, Argentina

Congreso; 35th Anniversary of the Hyperfine Interactions at La Plata; 2005

Instituto de Fisica La Plata

In order to study how the Ti replacement by Hf affects the crystalline and electronic structures of the pure perovskite SrHfO3, the hyperfine characterization of SrTixHf1-xO3 for x = 0.25, 0.50 and 0.75 is presented for the first time. The hyperfine electric quadrupole interaction at Ta probes was determined by Perturbed Angular Correlation spectroscopy. The samples were prepared by mixing high purity oxides or carbonates of the selected cations in stoichiometric proportions, and then using the high temperature solid state reaction procedure. The samples were characterized by X-ray diffraction technique at room temperature. No lines corresponding to the initial pure components were observed. The samples were then irradiated with thermal neutrons to produce the probe 181Hf/181Ta. The impurity concentration is 1:106 and no radiation damage was detected. In every sample the spin precession curves were measured from room temperature to 1000 C, with 50 C steps. To fit the data the conventional perturbation factor describing a static, axially asymmetric and disorder electric field gradient model was used. From this numerical analysis, the quadrupole frequency wQ, the asymmetry parameter h and the line width d were obtained as a function of temperature and composition.