%0 Journal Article
%A Nemes, Norbert Marcel
%A Tornos, J.
%A León Yebra, Carlos
%A Santamaría Sánchez-Barriga, Jacobo
%T Exotic magnetic anisotropy map in epitaxial La_(0.7)Ca_(0.3)MnO_(3) films on BaTiO_(3)
%D 2011
%@ 1098-0121
%U https://hdl.handle.net/20.500.14352/44550
%X We report the observation between 40 and 120 K of anomalous magnetic hysteresis loops in thin epitaxial films of La_(0.7)Ca_(0.3)MnO_(3) grown on ferroelectric BaTiO_(3). These hysteresis loops display extremely unusual features: after switching at coercivity, the magnetization overshoots the eventual high-field value. We study the strains in the film and substrate with x-ray diffraction and propose a model of two magnetic moment populations with different magnetoelastic anisotropies. The relative weights of both populations can be estimated by comparison with twin samples of La_(0.7)Ca_(0.3)MnO_(3) films on nonferroelectric SrTiO_(3). We propose that the observed magnetization overshoots the result from differences in the magnetostriction balance as the applied magnetic field increases. The picture of a nonuniform strain field in La_(0.7)Ca_(0.3)MnO_(3) on BaTiO_(3), caused by the corrugation of the ferroelectric domains in the rhombohedric phase of BaTiO_(3), is compatible with the magnetic granular behavior observed in the temperature and field dependences of the magnetization as well as in the low temperature magnetoresistance exhibited by the epitaxial film.
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