Polarized neutron reflectometry study of the magnetization reversal process in YBa2Cu3O7 /La2/3Ca1/3MnO3 superlattices grown on SrTiO3 substrates

Authors

J. Hoppler
H. Fritzsche
V. K. Malik
J. Stahn
G. P. Cristiani
H.-U. Habermeier
M. Rössle
Jan Honolka, Max-Planck-Institut für FestkörperforschungFollow
Axel Enders, University of Nebraska–LincolnFollow
C. Bernhard

Document Type

Article

Date of this Version

2010

Citation

PHYSICAL REVIEW B 82, 174439 (2010); DOI: 10.1103/PhysRevB.82.174439

Comments

Copyright 2010 The American Physical Society

Abstract

Using polarized neutron reflectometry we investigated the reversal of the magnetization of a high-T_c superconductor/ferromagnet superlattice that consists of eight bilayers of YBa₂Cu₃O₇(25.6 nm) /La_2/3Ca_1/3MnO₃(25.6 nm) grown on a SrTiO3 substrate. The measurements were performed during a magnetization hysteresis loop at 5 K. We obtained evidence that the reversal in the vicinity of the coercive field proceeds via the switching of micrometer-sized magnetic domains that are considerably larger than the typical domains of La_2/3Ca_1/3MnO₃. Furthermore, these large magnetic domains appear to be more strongly correlated along the vertical direction of the superlattice than along the lateral one. We provide evidence that this unusual behavior may be induced by the SrTiO₃ substrate which undergoes a series of structural phase transitions, some of which give rise to the formation of micrometer-sized surface facets that are tilted with respect to each other. These facets and the resulting strain fields are transmitted throughout the superlattice and thus may act as templates for the large magnetic domains in the La_2/3Ca_1/3MnO₃ layers whose magnetic properties are very susceptible to the lattice strain.