Anisotropic spin-density distribution and magnetic anisotropy of strained La1−xSr x MnO3 thin films: angle-dependent x-ray magnetic circular dichroism
Source abstract
Abstract
Abstract Magnetic anisotropies of ferromagnetic thin films are induced by epitaxial strain from the substrate via strain-induced anisotropy in the orbital magnetic moment and that in the spatial distribution of spin-polarized electrons. However, the preferential orbital occupation in ferromagnetic metallic La1−xSr x MnO3 (LSMO) thin films studied by x-ray linear dichroism (XLD) has always been found out-of-plane for both tensile and compressive epitaxial strain and hence irrespective of the magnetic anisotropy. In order to resolve this mystery, we directly probed the preferential orbital occupation of spin-polarized electrons in LSMO thin films under strain by angle-dependent x-ray magnetic circular dichroism (XMCD). Anisotropy of the spin-density distribution was found to be in-plane for the tensile strain and out-of-plane for the compressive strain, consistent with the observed magnetic anisotropy. The ubiquitous out-of-plane preferential orbital occupation seen by XLD is attributed to the occupation of both spin-up and spin-down out-of-plane orbitals in the surface magnetic dead layer.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Magnetic and transport properties of perovskites and related materials · Chemical and Physical Properties of Materials · Multiferroics and related materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (30)
Show source-provided references
1. Coey, J. M. D. Magnetism and Magnetic Materials. (Cambridge University Press, New York, NY, 2009).
2. Imada, M., Fujimori, A. & Tokura, Y. Metal-insulator transitions. Rev. Mod. Phys. 70, 1039–1263 (1998).10.1103/RevModPhys.70.1039 ↗
3. Konishi, Y. et al. Orbital-state-mediated phase-control of manganites. J. Phys. Soc. Jpn. 68, 3790–3793 (1999).10.1143/JPSJ.68.3790 ↗
4. Tsui, F., Smoak, M. C., Nath, T. K. & Eom, C. B. Strain-dependent magnetic phase diagram of epitaxial La0.67Sr0.33MnO3 thin films. Appl. Phys. Lett. 76, 2421–2423 (2000).10.1063/1.126363 ↗
5. Kwon, C. et al. Stress-induced effects in epitaxial (La0.7Sr0.3)MnO3 films. J. Magn. Magn. Mater. 172, 229–236 (1997).10.1016/S0304-8853(97)00058-9 ↗
6. Tebano, A. et al. Evidence of orbital reconstruction at interfaces in ultrathin La0.67Sr0.33MnO3 films. Phys. Rev. Lett. 100, 137401 (2008).10.1103/PhysRevLett.100.137401 ↗
7. Aruta, C. et al. Orbital occupation, atomic moments, and magnetic ordering at interfaces of manganite thin films. Phys. Rev. B 80, 014431 (2009).10.1103/PhysRevB.80.014431 ↗
8. Pesquera, D. et al. Surface symmetry-breaking and strain effects on orbital occupancy in transition metal perovskite epitaxial films. Nat. Commun. 3, 1189 (2012).10.1038/ncomms2189 ↗
9. Carra, P., Thole, B. T., Altarelli, M. & Wang, X. X-ray circular dichroism and local magnetic fields. Phys. Rev. Lett. 70, 694–697 (1993).10.1103/PhysRevLett.70.694 ↗
10. Stöhr, J. & König, H. Determination of spin- and orbital-moment anisotropies in transition metals by angle-dependent x-ray magnetic circular dichroism. Phys. Rev. Lett. 75, 3748–3751 (1995).10.1103/PhysRevLett.75.3748 ↗
11. Dürr, H. A. & van der Laan, G. Magnetic circular x-ray dichroism in transverse geometry: Importance of noncollinear ground state moments. Phys. Rev. B 54, R760–R763 (1996).10.1103/PhysRevB.54.R760 ↗
12. van der Laan, G. Microscopic origin of magnetocrystalline anisotropy in transition metal thin films. J. Phys. Condens. Matter 10, 3239 (1998).10.1088/0953-8984/10/14/012 ↗
13. van der Laan, G. Relation between the angular dependence of magnetic x-ray dichroism and anisotropic ground-state moments. Phys. Rev. B 57, 5250–5258 (1998).10.1103/PhysRevB.57.5250 ↗
14. Maruyama, T., Hojo, I., Nagamatsu, S.-i & Fujikawa, T. Theoretical study of angular-dependent L2,3-edge XMCD. J. Electron. Spectrosc. Relat. Phenom. 180, 46–52 (2010).10.1016/j.elspec.2010.04.003 ↗
15. Dürr, H. A. et al. Element-specific magnetic anisotropy determined by transverse magnetic circular x-ray dichroism. Science 277, 213–215 (1997).10.1126/science.277.5323.213 ↗
16. Mamiya, K. et al. Angle-resolved soft X-ray magnetic circular dichroism in a monatomic Fe layer facing an MgO(0 0 1) tunnel barrier. Radiat. Phys. Chem. 75, 1872–1877 (2006).10.1016/j.radphyschem.2005.07.042 ↗
17. van der Laan, G., Chopdekar, R. V., Suzuki, Y. & Arenholz, E. Strain-induced changes in the electronic structure of MnCr2O4 thin films probed by x-ray magnetic circular dichroism. Phys. Rev. Lett. 105, 067405 (2010).10.1103/PhysRevLett.105.067405 ↗
18. Koide, T. et al. Gigantic transverse x-ray magnetic circular dichroism in ultrathin Co in Au/Co/Au(001). J. Phys. Conf. Ser. 502, 012002 (2014).10.1088/1742-6596/502/1/012002 ↗
19. Furuse, M. et al. HTS vector magnet for magnetic circular dichroism measurement. IEEE Trans. Appl. Supercond. 23, 4100704 (2013).10.1109/TASC.2012.2236599 ↗
20. Thole, B. T., Carra, P., Sette, F. & van der Laan, G. X-ray circular dichroism as a probe of orbital magnetization. Phys. Rev. Lett. 68, 1943–1946 (1992).10.1103/PhysRevLett.68.1943 ↗
21. Koide, T. et al. Close correlation between the magnetic moments, lattice distortions, and hybridization in LaMnO3 and La1−xSr x MnO3+δ: Doping-dependent magnetic circular x-ray dichroism study. Phys. Rev. Lett. 87, 246404 (2001).10.1103/PhysRevLett.87.246404 ↗
22. Shibata, G. et al. Thickness-dependent ferromagnetic metal to paramagnetic insulator transition in La0.6Sr0.4MnO3 thin films studied by x-ray magnetic circular dichroism. Phys. Rev. B 89, 235123 (2014).10.1103/PhysRevB.89.235123 ↗
23. de Jong, M. P. et al. Evidence for Mn2+ ions at surfaces of La0.7Sr0.3MnO3 thin films. Phys. Rev. B 71, 014434 (2005).10.1103/PhysRevB.71.014434 ↗
24. Stoner, E. C. & Wohlfarth, E. P. A mechanism of magnetic hysteresis in heterogeneous alloys. Philos. Trans. R. Soc. London. Ser. A 240, 599–642 (1948).10.1098/rsta.1948.0007 ↗
25. Nakajima, R., Stöhr, J. & Idzerda, Y. U. Electron-yield saturation effects in L-edge x-ray magnetic circular dichroism spectra of Fe, Co, and Ni. Phys. Rev. B 59, 6421–6429 (1999).10.1103/PhysRevB.59.6421 ↗
26. Yoshimatsu, K., Horiba, K., Kumigashira, H., Ikenaga, E. & Oshima, M. Thickness dependent electronic structure of La0.6Sr0.4MnO layer in SrTiO3/La0.6Sr0.4MnO3/SrTiO3 heterostructures studied by hard x-ray photoemission spectroscopy. Appl. Phys. Lett. 94, 071901 (2009). 1–3.10.1063/1.3081016 ↗
27. Huijben, M. et al. Critical thickness and orbital ordering in ultrathin La0.7Sr0.3MnO3 films. Phys. Rev. B 78, 094413 (2008).10.1103/PhysRevB.78.094413 ↗
28. Horiba, K. et al. A high-resolution synchrotron-radiation angle-resolved photoemission spectrometer with in situ oxide thin film growth capability. Rev. Sci. Instrum. 74, 3406–3412 (2003).10.1063/1.1584093 ↗
29. Tanaka, A. & Jo, T. Resonant 3d, 3p and 3s photoemission in transition metal oxides predicted at 2p threshold. J. Phys. Soc. Jpn. 63, 2788–2807 (1994).10.1143/JPSJ.63.2788 ↗
30. Kokalj, A. XCrySDen—a new program for displaying crystalline structures and electron densities. J. Mol. Graphics Modell. 17, 176–179 (1999).10.1016/S1093-3263(99)00028-5 ↗