Thermodynamic conditions during growth determine the magnetic anisotropy in epitaxial thin-films of La0.7Sr0.3MnO3

J M VILA-FUNGUEIRIÑO; CONG TINH BUI; B RIVAS-MURIAS; E WINKLER; J MILANO; J SANTISO; F RIVADULLA

JOURNAL OF PHYSICS - D (APPLIED PHYSICS)

IOP PUBLISHING LTD

Lugar: Londres; Año: 2016 vol. 49 p. 315001 - 315001

0022-3727

The suitability of a particular material for use in magnetic devices is determined by theprocess of magnetization reversal/relaxation, which in turn depends on the magneticanisotropy. Therefore, designing new ways to control magnetic anisotropy in technologicallyimportant materials is highly desirable. Here we show that magnetic anisotropy of epitaxialthin-films of half-metallic ferromagnet La0.7Sr0.3MnO3 (LSMO) is determined by theproximity to thermodynamic equilibrium conditions during growth. We performed a seriesof x-ray diffraction and ferromagnetic resonance (FMR) experiments in two different sets ofsamples: the first corresponds to LSMO thin-films deposited under tensile strain on(0 0 1) SrTiO3 by pulsed laser deposition (PLD; far from thermodynamic equilibrium);the second were deposited by a slow chemical solution deposition (CSD) method, underquasi-equilibrium conditions. Thin films prepared by PLD show fourfold in-plane magneticanisotropy, with an overimposed uniaxial term. However, the uniaxial anisotropy is completelysuppressed in the CSD films. This change is due to a different rotation pattern of MnO6octahedra to accomodate epitaxial strain, which depends not only on the amplitude oftensile stress imposed by the STO substrate, but also on the growth conditions. Our resultsdemonstrate that the nature and magnitude of the magnetic anisotropy in LSMO can be tunedby the thermodynamic parameters during thin-film deposition.