Japanese Journal of Applied Physics · 1994 · 32 citations · 1 references
Natural SciencesMaterials SciencePhysicsCeramic MaterialsCeramicsSolid State PhysicsCurie TemperatureDielectric CeramicsDielectricsElectrical Properties Of CeramicsFerroelectric MaterialsPerovskite MaterialsDielectric ConstantPerovskite Crystal StructurePerovskite DielectricsPyroelectric CeramicsPyroelectric PropertiesPyroelectricitySpace Charge PolarizationValence Effects
A broad peak above the Curie temperature of lead iron niobate Pb(Fe 1/2 Nb 1/2 )O 3 may be related to interfaces at the grain boundary. The origin of the anomalous second peak is not clear. The Sr-substituted lead iron niobate Pb 1- x Sr x (Fe 1/2 Nb 1/2 )O 3 ceramics were prepared for the purpose of investigating this anomaly. The dielectric anomaly and pyroelectric current in this system at around 200° C may be explained by the space-charge polarization in the interfaces of the grain boundary due to ionic valence changes from Fe 3+ to Fe 2+ in the B-site of the perovskite structure.
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