Structural evolution of a high Tc ferroelectric (x)Bi(Zn1∕2Ti1∕2)O3–(1−x)PbTiO3 solid solution

We have studied the structural phase transition of solid solutions (x)Bi(Zn1∕2Ti1∕2)O3–(1−x)PbTiO3. The temperature evolution of the x-ray diffraction patterns of the θ-2θ scans around {110} has been performed to check the structural phase transitions: The (101)∕(011) peak shifts to a larger value, while the (110) peak shifts to a smaller value with increasing temperature. Finally, the peaks merge to the same value at the Curie temperature, indicating a tetragonal to the cubic phase transition. The structural phase transition temperature Tc coincides with the Curie temperature and increases as the increasing Bi(Zn1∕2Ti1∕2)O3 composition (x). The evolution of the lattice constant, unit cell volume, and tetragonality as functions of temperature and composition is discussed.