Theoretical Study of Antiferrodistortive Phase Transition in Strontium Titanate
- Received Date: 2009-04-15
- Spontaneous polarization, Dielectric permittivity, Free energy, Antiferrodis-tortive phase transition
Abstract: At 105 K, strontium titanate is known to undergo an antiferrodistortive transition transform-ing from cubic to tetragonal structure as a result of the rotation of the oxygen octahedral around a cubic axe. Based on the Curie principle, the order parameter is determined to be a third-order complete symmetry polarization tensor. To take into account of quantum effects,the dielectric permittivity is measured from Landau free energy, and the Curie Weiss-type behavior is analyzed. From crystallization chemistry viewpoint, the dielectric behavior at low temperature is connected to small radius of Sr2+, which is much easier to move around the oxygen octahedral than Ba2+ in BaTiO3 or Pb2+ in PbTiO3.
|Citation:||Yu-ping Cai, Dai-zhao Han, Ru-yun Ning. Theoretical Study of Antiferrodistortive Phase Transition in Strontium Titanate[J]. Chinese Journal of Chemical Physics , 2010, 23(2): 237-240. doi: 10.1088/1674-0068/23/02/237-240|