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Electrical Conduction Anomaly in Samarium‐Doped Barium Titanate
Author(s) -
GOODMAN G.
Publication year - 1963
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1963.tb13770.x
Subject(s) - samarium , electrical resistivity and conductivity , barium titanate , condensed matter physics , grain boundary , materials science , anomaly (physics) , doping , quantum tunnelling , ceramic , temperature coefficient , thermal conduction , mineralogy , composite material , chemistry , physics , inorganic chemistry , microstructure , quantum mechanics
Studies of both single crystals and ceramics of samarium‐doped BaTiO 3 having identical compositions show that the positive temperature coefficient (PTC) electrical resistivity anomaly originates at the grain boundaries of the ceramic. The grain‐boundary region is visualized as an electron exhaustion layer, 10 2 to 10 4 A thick, of much higher electrical resistivity than the interior of the grain. These findings are compatible with Heywang's barrier layer model, with possible tunneling or electron wave scattering models, and with elements of Saburi's local fields mechanism. Sufficient information to point to any one model is, however, not yet available.