SPACE-CHARGE EFFECTS ON FERROELECTRIC CERAMIC PARTICLE SURFACES

The anomalous dielectric absorption current of BaTiO3 ceramics when an electric field is applied at above the Curie point was measured. The results cannot be explained by the famous Maxwell-Wagner double layer theory. The total charge of the charging and discharging absorption current was more than 1000 muC/cm2. The giant space charge produces "internal bias field" in the opposite direction to the first applied field. Another space charge is generated during the aging process after poling at below the Curie point. In this report, two types of space charge effects are described and discussed respect to "space charge stabilized effects" for electromechanical strength and the difficulties of polarization reversal applications due to "space charge asymmetric effects".