Perturbed angular correlation study of 181Ta-doped PbTi1−xHfxO3 compounds

摘要: Abstract In this work, the hyperfine quadrupole interaction at Ta-doped PbTi1−xHfxO3 polycrystalline samples is studied for first time. Powders with x=0.25, 0.50 and 0.75 were prepared characterized by X-ray diffraction analysis. Perturbed Angular Correlation (PAC) analyses done as a function of temperature, using low concentration 181Ta nuclei probes. ferroelectric paraelectric phases these compounds two sites occupied For each site frequency, asymmetry relative distribution width parameters obtained temperature above below Curie (TC). One was assigned to regular Ti–Hf site, while other one some kind defect. The behavior analyzed in terms recent published phase diagram presence disorder TC. three compositions measured, present discontinuities which correspond ferroelectric–paraelectric transition. both it found broad frequency distributed interactions. electronic would be responsible line interaction.