Suppression of mixed-phase areas in highly elongated BiFeO3 thin films on NdAlO3 substrates
Lee, Jin Hong
Koo, Tae Yeong
Choi, Hong Chul
Shim, Ji Hoon
Date of Issue2012
School of Materials Science and Engineering
Mixed-phase areas are produced in highly elongated BiFeO3 (BFO) thin films as a consequence of strain relaxation. A (001) neodymium aluminate (NdAlO3; NAO) substrate (a∼3.747 Å) prominently suppresses the strain relaxation effect and prevents the formation of mixed-phase regions. This creates a pathway to the thick, quasipure, highly elongated phases required for magnetoelectric applications. We characterize the crystal structure, the interface between film and substrate, the surface morphology, and the ferroelectric domain structure of BFO films on NAO substrates and compare them with those of films on typical lanthanum aluminate substrates. The underlying mechanisms are discussed based on the intriguing nature of phase competition in bismuth ferrite phases using first principles density functional calculations for the misfit strain-dependent total energy.
Physical review B
© 2012 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The paper can be found at the following official DOI: [http://dx.doi.org/10.1103/PhysRevB.86.054417]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.