AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeM

Paper MI-WeM7
Self-assembled Ferroelectric/Ferrimagnetic BaTiO@sub3@-CoFe@sub2@O@sub4@ Nanostructures

Wednesday, November 17, 2004, 10:20 am, Room 304A

Session: Magnetic Nanostructures
Presenter: H. Zheng, University of Maryland, College Park
Authors: H. Zheng, University of Maryland, College Park
J. Wang, University of Maryland, College Park
Z. Ma, University of Maryland, College Park
L. Mohaddes-Ardabili, University of Maryland, College Park
T. Zhao, University of Maryland, College Park
S.R. Shinde, University of Maryland, College Park
S.B. Ogale, University of Maryland, College Park
M. Wuttig, University of Maryland, College Park
A. Roytburd, University of Maryland, College Park
L. Salamanca-Riba, University of Maryland, College Park
S.E. Lofland, Rowan University
D. Viehland, Virginia Tech
D.G. Schlom, Pennsylvania State University
R. Ramesh, University of California Berkeley
Correspondent: Click to Email
Ferroelectric/ferrimagnetic BaTiO@sub3@-CoFe@sub2@O@sub4@ (BTO-CFO) nanostructures have been synthesized by pulsed laser deposition using a single Ba-Ti-Co-Fe-Oxide ceramic target. Spinel CFO and perovskite BTO phases spontaneously separated during heteroepitaxial growth on single crystal SrTiO@sub3@ (001) substrates. It is shown that films are epitaxial in-plane as well as out-of -plane, with CFO nano-pillar arrays embedded in a BTO matrix. CFO pillars have uniform size and spacing. As the substrate temperature increases from 750 °C to 950 °C, the average lateral size of the pillars increases from ~9 nm to ~70 nm. Magnetic measurements exhibit that all the films have a large uniaxial magnetic anisotropy with an easy axis normal to the film plane. It is calculated that stress anisotropy is the main contribution to the anisotropy field. We measured the ferroelectric and piezoelectric properties of the films, which correspond to the present of BTO phase. The temperature dependent magnetic measurements illustrate a coupling between the two order parameters of polarization and magnetization by a change in magnetization at the ferroelectric Curie temperature. This approach to the formation of self-assembled ferroelectric/ferromagnetic nanostructures is generic and manifests itself in other such spinel-perovskite systems, thus making it of great interest and value to a broad materials community. This work is supported by the NSF-MRSEC under contract No. DMR-00-80008.