$(Na_{1/2}Bi_{1/2})TiO_3-PbTiO_3$ 고용체의 강유전 상전이 거동 |
홍국선, 조서용, 박승익1 |
서울대학교 공과대학 무기재료공학과 1미국 펜실베니아 주립대학 |
Ferroelectric Phase Transition Behavior in $(Na_{1/2}Bi_{1/2})TiO_3-PbTiO_3$ System |
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ABSTRACT |
The morphotropic phase boundary and phase transitions of the solid solutiion system, (1-x)(Na1/2Bi1/2)TiO3-PbTiO3+xPbTiO3 were studied by investigating changes in crystal structure, variations in permittivity with temperature, and calorimetric behavior. It was observed that the morphotropic phase boundary (MPB) of this solid solutiion system was at near 14 mol% of PbTiO3. Compositions containing less than 10mol% PbTiO3 (x<0.1) exhibited a phase transition, i.e. ferroelectric rhombohedrallongrightarrowparaelectric paraelectric cubic, with increasing temperature. Composition containing more than 14 mol% PbTiO3 (x 0.14) showed a phase transition from ferroelectric tetragonal to paraelectric cubic. In the composition range of 0.1$varepsilon$ (T) curve, which coincided with a phase transition from ferroelectric rhombohedral to an intermediate phase, was also found. |
Key words:
$(Na_{1/2}Bi_{1/2})TiO_3-PbTiO_3$, $PbTiO_3$, Morphotropic phase boundary, Phase transition |
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