Cation size effects-modified phase and PTCR development in Er3+ and Ca2+ co-doped BaTiO3 ceramics during sintering

被引：0
作者：
Da Silva, Ronaldo Santos [1 ]
M'Peko, Jean-Claude [1 ]
Da Costa Fontes, Lilian [1 ]
Hernandes, Antonio Carlos [1 ]
机构：
[1] Grupo Crescimento de Cristais e Materials Cerâmicos - GCCMC, Instituto de Física de São Carlos - IFSC, Universidade de São Paulo - USP, 13560-970 São Carlos - SP
来源：
Materials Research | 2009年 / 12卷 / 03期
关键词：
BaTiO[!sub]3[!/sub; Electrical properties; Phase development; PTCR;
D O I：
10.1590/s1516-14392009000300007
中图分类号：
学科分类号：
摘要：
Development of the positive temperature coefficient of resistivity (PTCR) in Er3+ and Ca2+ co-doped ferroelectric BaTiO3 was studied in this work, with Er3+ being used to act as a donor doping. Irrespective of all the materials showing high densities after sintering at 1200 to 1300 °C, these revealed insulator at the lowest sintering temperature, changing to semiconducting and PTCR-type materials only when the sintering temperature was further increased. Observations from X-ray diffraction help correlating this effect with phase development in this formulated (Ba,Ca,Er)TiO3 system, considering the formation of initially two separated major (Ba,Ca) TiO3- and minor (Ca,Er)TiO3-based compounds, as a consequence of cation size-induced stress energy effects. Thus, appearance and enhancement here of the semiconducting and PTCR responses towards higher sintering temperatures particularly involve the incorporation of Er 3+ into the major phase, rendering finally possible the generation and percolative-like" migration of electrons throughout the whole material."
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页码：287 / 290
页数：3
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