DocumentCode
3036521
Title
PTCR properties and aging characteristics in Y2O3 doped BaTiO3 ceramics with ZrO2 additions
Author
Roseman, R.D. ; Armstrong, T.R. ; Buchanan, R.C.
Author_Institution
Dept. of Mater. Sci. & Eng., Illinois Univ., Urbana, IL, USA
fYear
1990
fDate
6-8 Jun 1990
Firstpage
463
Lastpage
467
Abstract
The effects of yttria and zirconia additions to the BaTiO3 microstructure and the positive temperature coefficient of resistance (PTCR) effect are studied. Y2O3 and ZrO 2 were added to barium- and titanium-rich samples without the incorporation of SiO2, so that only the effects of each could be observed. Several aging studies were used to determine the type of changes which occur from added ZrO2. The stoichiometry was varied using Ba/Ti=1.003 and 0.997. Small ZrO2 additions to the Ti excess materials greatly affected the microstructures and within the limit of solubility lowered the resistivity by up to an order of magnitude and increased the rise at the Curie temperature (T c). ZrO2 additions degraded the PTCR properties for Ba excess samples. Various static and cyclic modes of aging were used to study the resistivity instability. ZrO2 additions were found to improve the degradation in resistivity in Ti excess materials. Without added ZrO2 the Ba excess materials showed smaller variations in resistivity in all modes
Keywords
ageing; barium compounds; ceramics; crystal microstructure; electrical conductivity of crystalline semiconductors and insulators; ferroelectric materials; stoichiometry; yttrium compounds; zirconium compounds; Curie temperature; Y2O3-BaTiO3-ZrO2; aging; ceramics; microstructure; positive temperature coefficient of resistance; resistivity instability; stoichiometry; Aging; Ball milling; Barium; Ceramics; Dielectric materials; Grain size; Heating; Internal stresses; Microstructure; Temperature;
fLanguage
English
Publisher
ieee
Conference_Titel
Applications of Ferroelectrics, 1990., IEEE 7th International Symposium on
Conference_Location
Urbana-Champaign, IL
Print_ISBN
0-7803-0190-0
Type
conf
DOI
10.1109/ISAF.1990.200289
Filename
200289
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