A stress-sensing ceramic device based on PTCR barium titanate

Author

Capurso, Joseph S. ; Schulze, Walter A.

Author_Institution

New York State Coll. of Ceramics, Alfred Univ., NY, USA

fYear

1991

fDate

33457

Firstpage

731

Lastpage

734

Abstract

Positive temperature coefficient of resistance (PTCR) barium titanate is used as the base material for a ceramic sensor which employs piezoresistivity to detect changes in applied stress. Tape-cast sheets of undoped (insulating) and PTCR (semiconducting) BaTiO₃ are laminated to produce a three-layer “trilaminate”-a sintered structure which has two PTCR layers separated by an insulating layer. The trilaminate is exposed to mechanical stress 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 the applied stress magnitude. The piezoresistivity coefficient (π) is calculated from the slope of the linear resistivity-stress response. Piezoresistivity results are presented versus PTCR layer composition (counterdopant species) and furnace cooling conditions (grain boundary oxidation level). These results are interpreted with respect to Heywang´s model of the gain boundary potential barrier

Keywords

barium compounds; electric sensing devices; ferroelectric semiconductors; grain boundaries; laminates; piezoceramics; piezoelectric transducers; piezoresistive devices; stress measurement; BaTiO₃; Heywang´s model; PTCR BaTiO₃; applied stress; four-point bend configuration; furnace cooling conditions; gain boundary potential barrier; grain boundary oxidation level; insulating layer; linear resistivity-stress response; mechanical stress; piezoresistivity coefficient; positive temperature coefficient of resistance; semiconducting layer; sensor; sintered structure; stress-sensing ceramic device; tape-cast sheets; trilaminate; Barium; Ceramics; Insulation; Piezoresistance; Semiconductivity; Semiconductor materials; Sheet materials; Stress; Temperature sensors; Titanium compounds;

fLanguage

English

Publisher

ieee

Conference_Titel

Applications of Ferroelectrics, 1994.ISAF '94., Proceedings of the Ninth IEEE International Symposium on

Conference_Location

University Park, PA

Print_ISBN

0-7803-1847-1

Type

conf

DOI

10.1109/ISAF.1994.522473

Filename

522473