ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The influence of Ba-excess and liquid phase sintering with SiO2 on the electrical conduction and microstructure in PTCR BaTiO3 has been investigated. Dense (95–96%), small grain (5–10 μm) PTCR materials were obtained in Ba-excess (Ba/Ti = 1.006) BaTiO3. The materials exhibit low room temperature resistivity ρRT (100–102 Ω·cm) and high PTCR respond (more than 5 orders). Solid state sintering was found to inhabit the semiconducting and PTCR behavior in Ba-excess materials. Liquid phase sintering, using SiO2 in the Ba-excess BaTiO3, resulted in low ρRT and significant PTCR response. Through domain observation, interior “Polaron deficient zones” were found in samples which exhibit limited liquid phase sintering, leading to non-uniform directional domains and low charge carrier mobility. Proper control of the SiO2 concentration was found critical for obtaining uniform directional domain microstructures and low ρRT.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004624918910
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