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Piezoresistivity in PTCR Barium Titanate Ceramics: I, Experimental Findings
Author(s) -
Capurso Joseph S.,
Schulze Walter A.
Publication year - 1998
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.1151-2916.1998.tb02339.x
Subject(s) - materials science , barium titanate , composite material , sintering , temperature coefficient , ceramic , titanate , layer (electronics) , barium , doping , stress (linguistics) , metallurgy , optoelectronics , linguistics , philosophy
Positive temperature coefficient of resistance (PTCR) barium titanate is the active material in a ceramic sensor which employs piezoresistivity to detect changes in applied stress. High‐purity, chemically prepared barium titanate is donor‐doped with 0.30 at.% lanthanum, and <0.10 at.% of a transition‐metal counterdopant may be added to enhance the PTCR effect. Tape‐cast sheets of undoped and PTCR BaTiO 3 are laminated to produce a three‐layer “trilaminate”—a sintered structure which has two semiconducting PTCR layers separated by an insulating layer. The trilaminate is stressed in a four‐point bend configuration (placing one semiconducting layer completely in tension, the other in compression), and the resistivities for both stress states are measured concurrently as functions of applied stress and temperature. Results are presented for various semiconducting layer compositions and sintering conditions.