Competing phases in BiFeO3 thin films under compressive epitaxial strain

B. Dupé (1) , Infante I. Canero (1) , G. Geneste (1) , P.E. Janolin (1) , M. Bibes (2) , A. Barthelemy (2) , S. Lisenkov (3) , L. Bellaiche (4) , S. Ravy (5) , B. Dkhil (1)

1 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides
2 IPNO - Institut de Physique Nucléaire d'Orsay
3 Department of Physic
4 Department of Physics Department [Fayetteville]
5 SSOLEIL - Synchrotron SOLEIL

Combining density-functional calculations and x-ray diffraction experiments, we show that BiFeO3 epitaxially grown under compressive strain on cubic substrates evolves from the monoclinic Cc phase resulting from the strain-induced deformation of the ground-state rhombohedral R3c phase to the monoclinic Cm phase with increasing misfit, the transition being at about −4.5%/−5.5%. Moreover, the polarization of the Cc phase only rotates instead of increasing for misfit strain ranging from 0% to −4%, due to a strong coupling between polar displacements and oxygen octahedra tilts. This strong interaction is of interest for multiferroics where usually both structural degrees of freedom coexist.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

B. Dupé, Infante I. Canero, G. Geneste, P.E. Janolin, M. Bibes, et al.. Competing phases in BiFeO3 thin films under compressive epitaxial strain. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2010, 81 (144128), pp.144128-5. ⟨10.1103/pHYSrEVb.81.144128⟩. ⟨hal-00577838⟩