Metastable perovskite Bi1-xLaxFe0.5Sc0.5O3 phases in the range of the compositional crossover

Perovskite ceramics of the Bi1- xLaxFe0.5Sc0.5O3 composition (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 the Imma(00γ)s00 superspace group to the non-polar Pnma phase occurs in the narrow range between x = 0.33 and x = 0.34 with no phase coexistence. The features of this compositional crossover are discussed in comparison with that observed in the Bi1- xLaxFeO3 system.publishe

Low frequency noise characteristics of BaTiO3-NiFe2O4 composites at phase transition

In this work we present detailed investigation of low frequency noise characteristics of BaTiO3-NiFe2O4 ceramic composites of different percentage of NiFe2O4. At the particular temperatures (that gets under the broad maximum of dielectric permittivity observed around 300 K) very intensive few separate peaks of random telegraph noise signal were observed. It shows that phase transition in the investigated materials goes through separate stages instead of the smeared out one. Characteristic times of the physical processes during the phase transition are close to one millisecond, and activation energy is around (0,340,49) eV