Half-metallicity in a \chem{BiFeO_3/La_{\frac{2}{3}}Sr_{\frac{1}{3}}MnO_3} superlattice: A first-principles study

Abstract

PACS 73.20.-r -Electron states at surfaces and interfaces PACS 75.70.-i -Magnetic properties of thin films, surfaces, and interfaces PACS 78.20.-e -Optical properties of bulk materials and thin films Abstract -We present first-principles results for the electronic, magnetic, and optical properties of the BiFeO3/La 2 3 Sr 1 3 MnO3 heterostructure as obtained by spin-polarized calculations using density functional theory. The electronic states of the heterostructure are compared to those of the bulk compounds. Structural relaxation turns out to have only a minor impact on the chemical bonding, even though the oxygen octahedra in La 2 3 Sr 1 3MnO3 develop some distortions due to the interface strain. While a small charge transfer affects the heterointerfaces, our results demonstrate that the half-metallic character of La 2 3 Sr 1 3 MnO3 is fully maintained.

Superior Properties of Energetically Stable La2/3Sr1/3MnO3/Tetragonal BiFeO3 Multiferroic Superlattices

“…The energetically favorable configuration after the structural optimization, see Figure 1c, is LaO-terminated with interfacial O atoms located on top of interfacial Fe atoms and has sep W =-5.13 eV. This is consistent with the previous findings for the supercell consisting of LSMO and rhombohedral BFO 18,22 and is also in a similar LSMO/YMnO 3 system, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 -9 -1c) is 1.56 Å. More specifically, the O atoms are shifted out of the cationic plane, see Therefore, the BFO is subjected to a reduced ferroelectric polarization.…”

“…17 Jilili et al have found that the LSMO/rhombohedral BFO superlattice maintains the half-metallic character of bulk LSMO. 18 Moreover, Guo et al have discovered that the anomalies in the temperature-dependent ferromagnetic resonance spectra of LSMO occur at the transition temperature of Fe polarization, indicating a strong interfacial coupling between Fe and Mn. 19 Yu et al have reported a significant exchange bias for the coupling between LSMO and rhombohedral BFO using the X-ray circular dichroism method.…”

First principles prediction of interfacial magnetoelectric coupling in tetragonal La2/3Sr1/3MnO3/BiFeO3 multiferroic superlattices

“…5 So far, the LSMO/R-BFO bilayers have been a topic of much interest and debate. [6][7][8] X-ray magnetic circular dichroism measurements have demonstrated a significant exchange bias for the coupling between them mediated by an interfacial magnetic state, 9 and it is supposed to have different origins of the interfacial Fe ferromagnetic ordering like strong Mn-Fe hybridization, 9 Fe-O-Fe bond angle alteration and suppression of octahedral tiltings near the interface, 10 charge and orbital ordering, 11 and Fe/Mn intermixing. 12 The magnitude of induced Fe magnetization is proved to be sensitive to the size of the band gap of BFO.…”

Electric Field Modulation on Special Interfacial Magnetic States in Tetragonal La2/3Sr1/3MnO3/BiFeO3 Heterostructures

“…Aimed at investigating the interfacial magnetic order of BFO, all of four models contain the FeO 2 terminations. For LSMO, we focus on the LaO terminations first, which are the most stable interfacial configuration both in LSMO/BFO and LSMO/YMnO 3 heterostructures as calculated previously. ,− We further build the MnO 2 terminations, which contain opposite interfacial I and II layers with respect to LaO terminations. Two opposite directions of ferroelectric polarizations in BFO are analyzed in the two terminations, respectively, as shown in Figure .…”