Dual Antiferromagnetic Coupling atLa0.67Sr0.33MnO3/SrRuO3Interfaces

Abstract

We have studied the magnetic hysteresis cycle of La0.67Sr0.33MnO3/SrRuO3 antiferromagnetically coupled bilayers, by magnetometry and polarized neutron reflectometry. A positive exchange bias as well as an unusual asymmetry are observed on the magnetic reversal process of the La0.67Sr0.33MnO3 layer. Through an extended Stoner-Wohlfarth model comprising the magnetic anisotropy of both layers, we give experimental evidence that this asymmetry originates from two different but well-defined antiferromagnetic coupling strengths at the interface between the two magnetic oxides. The possible origin of this dual coupling is discussed in view of our experimental results.

Properties of manganite/ruthenate superlattices with ultrathin layers

“…Indeed, spin polarized neutron reflectometry measurements on 5/12 and 5/20 LSMO/SRO superlattices show that the SRO magnetic moments close to the interface and the LSMO magnetic moments lie in the superlattice plane, whereas the SRO magnetic moments in the cores of the SRO layers are rotated toward the out-of-plane direction [41]. A similar conclusion was reached by Solignac et al [42] on LSMO/SRO bilayers by magnetometry and polarized neutron reflectometry measurements. Therefore, it appears that the magnetic moment direction in LSMO/SRO superlattices is determined by the bulk magnetocrystalline anisotropy of the constituents and the strong antiferromagnetic interlayer coupling; a structural transition of the SRO layers does not seem to occur.…”

Ferromagnetic oxide heterostructures on silicon

“…[14,[7][8][9][10][11] The spin magnetic moment of this sample is estimated at 1.2 µ B per Ru 4+ ion, consistent with previously reported values (1.1-1.6 µ B per Ru 4+ ion) for the bulk SRO thin films. As shown by the curve in red, the sample with only LCMO layer exhibits characteristic [4,5] T C at about 240 K. The saturation magnetization is estimated at 3.…”

“…As shown by the curve in red, the sample with only LCMO layer exhibits characteristic [4,5] T C at about 240 K. The saturation magnetization is estimated at 3. [6,[7][8][9][10][11] on relaxed SRO thin films. The M-H curve (in red) recorded from LCMO layer also reveals a clear saturation behavior characterized by H c of 625 Oe (see inset of Fig.…”

“…In these heterostructures interesting magnetic properties such as antiferromagnetic exchange coupling and its cross-over to ferromagnetic exchange coupling [7][8][9][10][11] have been identified. Despite the fact that La 0.7 Ca 0.3 MnO 3 (LCMO) shares similar electronic and magnetic properties with LSMO, there has been no report on the epitaxial growth and investigation of magnetic properties of LCMO when it is interfaced with SRO layer on any substrate.…”

Evidence for spin-triplet superconducting correlations in metal-oxide heterostructures with noncollinear magnetization

“…An in-plane magnetic field of about 1 T is needed to turn the vector of magnetization of the SRO layer collinear to the magnetization of the LSMO layer [31]. Recent PNR experiments on LSMO/SRO bilayers have revealed noncollinear magnetic order resulting from a competition between the magnetocrystalline anisotropy and the antiferromagnetic exchange coupling across the interface [33][34][35]. The previous transport study of LSMO/SRO bilayers sandwiched between two superconducting Nb and YBa 2 Cu 3 O 6+x layers indicated the presence of the Josephson current in systems with a total thickness of the LSMO/SRO bilayer more than ξ F [36].…”