Integration of sputter-deposited multiferroic CoFe2O4-BiFeO3 nanocomposites on conductive La0.7Sr0.3MnO3 electrodes

Seung Han Lee; Guo Tian; Tae Cheol Kim; Hyun Kyu Jung; Jun Woo Choi; Frederick J Walker; Charles H Ahn; Caroline A Ross; Dong Hun Kim

doi:10.1088/1361-6528/aaf7cd

Integration of sputter-deposited multiferroic CoFe₂O₄-BiFeO₃ nanocomposites on conductive La_0.7Sr_0.3MnO₃ electrodes

Nanotechnology. 2019 Mar 8;30(10):105601. doi: 10.1088/1361-6528/aaf7cd. Epub 2018 Dec 11.

Authors

Seung Han Lee¹, Guo Tian, Tae Cheol Kim, Hyun Kyu Jung, Jun Woo Choi, Frederick J Walker, Charles H Ahn, Caroline A Ross, Dong Hun Kim

Affiliation

¹ Department of Materials Science and Engineering, Myongji University, Yongin, Republic of Korea.

PMID: 30537681
DOI: 10.1088/1361-6528/aaf7cd

Abstract

The structure, magnetic and ferroelectric properties of sputtered epitaxial CoFe₂O₄-BiFeO₃ (CFO-BFO) nanocomposite thin films grown on La_0.7Sr_0.3MnO₃ (LSMO) layers on (001) oriented SrTiO₃ (STO) substrates and on STO-buffered Si are described. The as-grown LSMO thin films were smooth and poorly conductive but the resistivity was reduced and the surfaces roughened after annealing. Cosputtered CFO and BFO on STO formed vertically aligned nanostructures consisting of epitaxial spinel CFO pillars within a perovskite BFO matrix, but the rough surface of the annealed LSMO film promoted additional CFO pillar orientations. A reorientation of the CFO magnetic easy axis to an in-plane direction occurred as the LSMO became thicker due to changes in the strain state of the CFO pillars. The LSMO underlayer enabled the ferroelectric response of the BFO to be measured. Nanocomposites were grown onto LSMO/SrTiO₃/Si which provides a path towards large scale integration of electrically contacted nanocomposites on Si.