Structural instabilities and sequence of phase transitions in SrBi${}_2$Ta${}_2$O${}_9$ and SrBi${}_2$Nb${}_2$O${}_9$ from first principles and Monte Carlo simulations

Urko Petralanda, I. Etxebarria

Despite their structural similarities, SrBi${}_2$Ta${}_2$O${}_9$ (SBT) and SrBi${}_2$Nb${}_2$O${}_9$ (SBN) undergo a different sequence of phase transitions. The phase diagram of SBT as a func…