BARC/PUB/2011/1100

 
 

Pressure dependent phase transitions in (Pb,Ca)TiO3: Determination of structure using high pressure synchrotron X-ray and Raman studies

 
     
 
Author(s)

Chandra, A.; Tyagi, A. K.; Vijaykumar, V.; Mukherjee, G. D.; Boehler, R.

Source

Journal of Electroceramics, 2011. Vol. 26: pp. 191-199

ABSTRACT

Pressure dependent studies on technologically important ferroelectric material Pb0.70Ca0.30TiO3 show the occurrence of a new hitherto unreported pressure dependent phase transition around 4 GPa. In the pressure range 4– 14 GPa, the parent tetragonal (P4mm) phase of Pb0.70Ca0.30TiO3 transforms in to a monoclinic (Cm) phase before attaining its paraelectric cubic (Pm3m) phase around 15 GPa. High pressure Raman studies reveal the presence of a critical pressure above which the ferroelectric phase starts to reappear in the paraelectric phase. This critical pressure is found to be much lower than the critical pressure observed in pure PbTiO3. Possible reasons for this lowering of the critical pressure are presented.

 
 
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