Sharp low frequency dissipative effects in tetragonal BaTiO3 ceramics

Mechanical anomalies damping peaks sharper than Debye peaks, in contrast to a broad relaxation peak were observed in tetragonal barium titanate ceramic via broadband viscoelastic spectroscopy at low frequencies 10 Hz at ambient temperature after aging at 90 °C for 15 h. The sharp peaks disappear after aging above the Curie point 150 °C for 10 h . Mechanical anomalies are tentatively attributed to negative stiffness heterogeneity, the mechanism of which is proposed based upon the theory of symmetry-conforming short-range order property of point defects. © 2010 American Institute of Physics. doi:10.1063/1.3283920