An Experimental Study of Polarization Effects in Barium Titanate Ceramics

Abstract

The electromechanical coupling in barium titanate ceramics is studied as a function of external bias for thickness resonances in the ultrasonic frequency range. The losses associated with the heating of resonant transducers are shown to be primarily of mechanical rather than dielectric origin. The response near coercive field strengths indicates that the rearrangements of domain patterns take place in at least two separate forms. The relationships of the subsidiary responses, which are observed in ceramics under suitable driving conditions, to the state of internal polarization are discussed. Domain processes of the kind assumed in this study furnish an explanation for the observed constriction of dielectric hysteresis loops.

Biased lead zirconate titanate as a high-power transduction material

“…For continuous operation, in which the heating due to losses associated with a hysteresis loop can cause the temperature to exceed the Curie point, they showed that biasing could reduce the hysteresis loop area, achieving temperature stabilization, and allowing higher drive fields. Hueter et al 7 followed up on the loss-factor reduction aspects of Ref. 6, but a͒ Currently on Intergovernmental Personnel Act ͑IPA͒ assignment at NUWC, Newport, RI 02841. noted that when mechanical losses are dominant ͑in comparison with dielectric losses͒, biasing does not provide much benefit.…”