Univ. Paris-Saclay

Service de Physique de l'Etat Condensé

Conversion polymorphism in high-pressure stabilized ABO3 phases
Andrei SALAK - Department of Materials and Ceramics Engineering / CICECO University of Aveiro, Portugal
Mercredi 10/07/2019, 11:15-12:15
SPEC Salle Itzykson, Bât.774, Orme des Merisiers

 

Séminaire spécialisé proposé par Antoine Barbier

Abstract :
High-pressure synthesis is a powerful method of production of new metastable materials with original crystal structures and exotic properties. In particular, this method is widely used to obtain perovskite phases since the perovskite structure is very compact and often provides the smallest unit cell volume. In the present work, we report an observation of unusual irreversible phase transformations upon post-synthesis thermal treatment between numerous metastable perovskite phases in the high-pressure stabilized BiFe1-yScyO3 series. In this rather simple system, we have revealed at least three compositional ranges where the post-synthesis annealing results in appearance of different perovskite polymorphs with new combinations of structural distortions and magnetic orders. We refer this behaviour as a conversion polymorphism and believe that this is a general phenomenon which can be found in many other systems and can be used to obtain novel materials with interesting properties.

 

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