Metastable perovskite Bi 1- x La x Fe 0.5 Sc 0.5 O 3 phases in the range of the compositional crossover.

Perovskite ceramics of the Bi1-xLaxFe0.5Sc0.5O3composition (0.30 ≤x≤ 0.35) that cannot be sintered in bulk form as a single phase using the conventional ceramic route were successfully prepared using the high-pressure/high-temperature technique. It has been shown that the room-temperature compositional crossover from the antipolar phase whose incommensurate modulation of displacements of Bi/La and oxygen is described by theImma(00γ)s00 superspace group to the non-polarPnmaphase occurs in the narrow range betweenx= 0.33 andx= 0.34 with no phase coexistence. The features of this compositional crossover are discussed in comparison with that observed in the Bi1-xLaxFeO3system. [ABSTRACT FROM PUBLISHER]