Sharp low frequency dissipative effects in tetragonal BaTiO3 ceramics

Abstract

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.