Ferroelectric and piezoelectric properties of SrBi2Ta2O9

R. MACHADO; M. G. STACHIOTTI; M. SEPLIARSKY

Rio de Janeiro

Conferencia; 11th International Conference on Advanced Materials (ICAM2009).; 2009

 The phase transition sequence and the evolution of dielectric and piezoelectric properties of SrBi2Ta2O9 areinvestigated using a shell model with parameters fitted to first-principles calculations. The simulated phase diagram shows the existenceof an intermediate orthorhombic paraelectric phase between the high-symmetry tetragonal and the ferroelectric orthorhombic phase. Weshow that this intermediate phase can be also detected from the anisotropy of dielectric response of the material. Finally, piezoelectricproperties along crystallographic directions are also investigated