Title :
Grain boundary behaviors of ferroelectric ceramics above Curie point
Author :
Okazaki, Kiyoshi ; Maiwa, Hiroshi ; Hagiwara, M. ; Sugihara, Sunao
Author_Institution :
Dept. of Mater. Sci. & Ceramic Technol., Shonan Inst. of Technol., Fujisawa, Japan
fDate :
30 Aug-2 Sep 1992
Abstract :
In place of the Maxwell-Wagner double-layer theory for the anomalous dielectric absorption current, a novel space charge model based on experimental results for BaTiO3 ceramics when an electric field is applied above the Curie point is proposed. This model can explain the very large charge (exceeding 1000 μC/cm2) stored during charging by DC field application above the Curie point and the time dependence of the discharging absorption current. When the DC field is applied at room temperature to (Sr,Ba)TiO3 ceramics with a Curie point of -50°C, the behavior corresponds to that of BaTiO3 when a DC field is applied above the Curie point. The sample can have a giant space charge polarization. The apparent pyroelectric current was measured, with attention given to the role of grain boundaries
Keywords :
barium compounds; ceramics; ferroelectric Curie temperature; ferroelectric materials; grain boundaries; pyroelectricity; space charge; strontium compounds; (SrBa)TiO3 ceramics; BaTiO3 ceramics; Curie point; anomalous dielectric absorption current; apparent pyroelectric current; charging; direct current field; discharging absorption current; electric field; ferroelectric ceramics; giant space charge polarization; grain boundaries; space charge model; time dependence; Absorption; Ceramics; Current measurement; Dielectrics; Ferroelectric materials; Grain boundaries; Polarization; Pyroelectricity; Space charge; Temperature;
Conference_Titel :
Applications of Ferroelectrics, 1992. ISAF '92., Proceedings of the Eighth IEEE International Symposium on
Conference_Location :
Greenville, SC
Print_ISBN :
0-7803-0465-9
DOI :
10.1109/ISAF.1992.300633
