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Positive Temperature Coefficient of Resistivity Effect in Undoped, Atmospherically Reduced Barium Titanate
Author(s) -
Alles Aldo Bologna,
Amarakoon Vasantha R. W.,
Burdick Ver L.
Publication year - 1989
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.1151-2916.1989.tb05970.x
Subject(s) - electrical resistivity and conductivity , barium titanate , temperature coefficient , fluorine , materials science , barium , mineralogy , analytical chemistry (journal) , oxygen , acceptor , titanate , inorganic chemistry , chemistry , ceramic , condensed matter physics , composite material , metallurgy , organic chemistry , physics , electrical engineering , engineering , chromatography
A sharp positive temperature coefficient of resistivity effect for undoped, fluorinated BaTiO 3−x samples was observed. The qualitative agreement between the behavior of BaTiO 3−x and La‐doped BaTiO 3 , with respect to the trap density at the boundaries, suggests that in the absence of counterdopants such as Mn, the main origin of surface acceptor states is chemisorbed gases. Impedance analysis indicates that, under the conditions of the present work, fluorine seems not to diffuse in significant amounts into the lattice. The treatment of the fluorinated samples in inert/reducing atmospheres did not markedly decrease the resistivity jump, suggesting that fluorine might be chemisorbed more strongly than oxygen. The composition of two different liquid phases, produced by excess titania and silica additions, did not have an important effect on the resulting properties.