Spontaneous Strain as Order Parameter to Describe the Phase Transition in La3+ Doped Pbtio3 Ferroelectric Perovskite
Spontaneous strains of lanthanum doped PbTiO3 compound were determined from the temperature dependence of the unit cell parameters. The critical temperature was determined by using the spontaneous strain as order parameter. The calculated value of the critical temperature agrees with that obtained through differential scanning calorimetric measurements. The temperature dependence of the spontaneous polarization was also estimated through the components of the uniform elastic deformations parallel and perpendicular to the  crystallographic direction of the perovskite structure.
This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.