title: Magnetic Phase Formation in Self-Assembled Epitaxial BiFeO3-MgO and BiFeO3-MgAl2O4 Nanocomposite Films Grown by Combinatorial Pulsed Laser Deposition.
abstract: Self-assembled epitaxial BiFeO3-MgO and BiFeO3-MgAl2O4 nanocomposite thin films were grown on SrTiO3 substrates by pulsed laser deposition. A two-phase columnar structure was observed for BiFeO3-MgO codeposition within a small window of growth parameters, in which the pillars consisted of a magnetic spinel phase (Mg,Fe)3O4 within a BiFeO3 matrix, similar to the growth of BiFeO3-MgFe2O4 nanocomposites reported elsewhere. Further, growth of a nanocomposite with BiFeO3-(CoFe2O4/MgO/MgFe2O4), in which the minority phase was grown from three different targets, gave spinel pillars with a uniform (Mg,Fe,Co)3O4 composition due to interdiffusion during growth, with a bifurcated shape from the merger of neighboring pillars. BiFeO3-MgAl2O4 did not form a well-defined vertical nanocomposite in spite of having lower lattice mismatch, but instead formed a two-phase film with in which the spinel phase contained Fe. These results illustrate the redistribution of Fe between the oxide phases during oxide codeposition to form a ferrimagnetic phase from antiferromagnetic or nonmagnetic targets.
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|Department of Materials Science and Engineering, Myongji University , Yongin 120-728, Republic of Korea.
authors.forename: Dong Hun
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|School of Materials Science and Engineering, Harbin Institute of Technology , Harbin 150001, People's Republic of China.
authors.forename: XueYin
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Materials Science and Engineering, Myongji University , Yongin 120-728, Republic of Korea.
authors.forename: Tae Cheol
authors.initials: TC
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Myongji University , Yongin 120-728, Republic of Korea.
authors.forename: Yun Jae
authors.initials: YJ
authors.lastname: Eun
authors.affiliation: Department of Materials Science and Engineering, Myongji University , Yongin 120-728, Republic of Korea.
authors.forename: Taeho
authors.initials: T
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Myongji University , Yongin 120-728, Republic of Korea.
authors.forename: Sung Gyun
authors.initials: SG
authors.lastname: Jeong
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Ross
keywords: BiFeO3; combinatorial pulsed laser deposition; epitaxy; multiferroic; perovskite; self-assembled oxide nanocomposite; spinel; thin film oxide