Preparation of a heteroepitaxial LaxSryMnzO3/BiFeO3 bilayer by r.f. magnetron sputtering with various oxygen gas flow ratios

H. Naganuma; T. Ichinose; H. A. Begum; S. Sato; X. F. Han; T. Miyazaki; In-T. Bae; M. Oogane; Y. Ando

doi:10.1063/1.4893998

AIP Advances (Aug 2014)

Preparation of a heteroepitaxial LaxSryMnzO3/BiFeO3 bilayer by r.f. magnetron sputtering with various oxygen gas flow ratios

H. Naganuma,
T. Ichinose,
H. A. Begum,
S. Sato,
X. F. Han,
T. Miyazaki,
In-T. Bae,
M. Oogane,
Y. Ando

Affiliations

H. Naganuma: Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
T. Ichinose: Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
H. A. Begum: Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
S. Sato: Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
X. F. Han: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
T. Miyazaki: Group of Communication Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
In-T. Bae: Small Scale Systems Integration and Packaging Center, State University of New York at Binghamton, Binghamton, NY 13902, U.S.A.
M. Oogane: Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
Y. Ando: Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan

DOI: https://doi.org/10.1063/1.4893998
Journal volume & issue: Vol. 4, no. 8
pp. 087133 – 087133-10

Abstract

Read online

BiFeO3 (BFO) and LaxSryMnzO3 (LSMO) films were epitaxially grown on SrTiO3 (100) substrates by r.f. magnetron sputtering with various oxygen gas flow ratios (FO2). Compositional ratios of each atom in both of BFO and LSMO could be controlled kept to around 10 at.% by changing FO2. Adjusting the compositional ratio to La0.35Sr0.15Mn0.5O3 not only increase Tc of LSMO but also produces sufficient oxygen to form a perovskite lattice. For an LSMO/BFO heterostructure, detailed observation by cross sectional transmission electron microscopy (TEM) revealed that the lattice of rhombohedral (SG: R-3c) LSMO was shrank by a clamping effect from the SrTiO3 substrates, and then the BFO was grown in two layers: (i) an interfacial BFO layer (7 nm thick) with evenly shrunk a-axis and c-axis, and (ii) an upper BFO layer (25 nm thick) expanded along the c-axis. Neither misfit strain nor dislocations appeared at the interface between the shrunken BFO and LSMO layers, and these heterostructures did not show exchange bias. These results suggest that BFO is suitable for a tunneling barrier combine with LSMO electrode.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

About the journal