Enhanced Piezoelectric and Ferroelectric Properties of Ion‐Doped BaTiO₃

The ferroelectric, dielectric, and piezoelectric characteristics of ion‐doped BaTiO 3 (BTO) have been investigated using the transverse Ising model in combination with Green's function technique. The results reveal that doping BTO at the Ba site with Bi or Pb ions leads to enhanced ferroelectric, dielectric, and piezoelectric responses. Moreover, both the Curie temperature and the electrostrictive coefficient exhibit increased values compared to undoped BTO. Doping effects at the Ti site have also been examined, as well as at Ba or/and Ti sites. Additionally, the Curie temperature is found to rise with Ca doping at the Ba site and with (Zn,Co) codoping at the Ba and Ti sites. These doping effects have been analyzed from a microscopic perspective. Importantly, it is demonstrated for the first time that a competition arises between the tunneling frequency and the exchange interaction, attributable to differences in ionic radii and atomic mass between the dopant and host ions. The observed enhancements in the piezoelectric and ferroelectric properties of doped and codoped BTO highlight their significant potential for use in sensor and piezoelectric device applications.