Temperature-induced phase transition and morphotropic phase boundary in the nanocrystalline Pb<sub>1-x</sub>Sr<sub>x</sub>TiO<sub>3</sub> system
Jinfang Meng; Guangtian Zou; Yanzhang Ma; Xiaohui Wang; Muyu Zhao; Jinfang Meng; State Key Lab. for Superhard Mater., Jilin Univ., Changchun, China; Guangtian Zou; State Key Lab. for Superhard Mater., Jilin Univ., Changchun, China; Yanzhang Ma; State Key Lab. for Superhard Mater., Jilin Univ., Changchun, China; Xiaohui Wang; State Key Lab. for Superhard Mater., Jilin Univ., Changchun, China; Muyu Zhao; State Key Lab. for Superhard Mater., Jilin Univ., Changchun, China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1994-08-08
Аннотация:
The Raman spectra in the nanocrystalline Pb<sub>1-x</sub>Sr<sub>x</sub>TiO<sub>3</sub> system show that the morphotropic phase transition from the tetragonal phase to the cubic structure occurs at x<sub>c</sub>=0.57 and it can be associated with 'softening' of the lowest-frequency E(TO) phonon mode. The phase transition temperature in Pb<sub>0.8</sub>Sr<sub>0.2</sub>TiO<sub>3</sub> decreases with decreasing grain size. The disappearance of the ferroelectric phase of Pb<sub>0.8</sub>Sr<sub>0.2</sub>TiO<sub>3</sub> has been discussed as a function of grain size. The correlation between the temperature-induced and the Sr-concentration-induced phase transition in nanocrystalline Pb<sub>1-x</sub>Sr<sub>x</sub>TiO<sub>3</sub> has been observed.
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