Ferroelectric transition in Sr- and W-Doped BaTiO₃ solid solutions

We synthesized Sr- and W-doped BaTiO₃ (BTO) polycrystals by using a solid-state reaction method. The X-ray diffraction results showed that Sr andWatoms occupied the Ba and Ti sites in tetragonal BTO, respectively, and there were changes in the lattice constants and the volumes in the Sr- and W-doped BTO. We found a change in the latent heat and the Curie temperature (TC) during the transition between the ferroelectric and paraelectric phases while increasing the contents of Sr andWin the Sr- andW-doped BTO. This can be explained by the fact that the doping of Sr and W atoms in BTO prevented a distinct transition between the ferroelectric tetragonal and paraelectric cubic structures by decreasing the c/a ratio to a value close to unity. This study shows a way toward a strategy for modulating a crystal structure by using proper dopants for future applications in ferroelectricity-based devices.