skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electronic and magnetic properties of off-stoichiometric Co{sub 2}Mn{sub β}Si/MgO interfaces studied by x-ray magnetic circular dichroism

Abstract

We have studied the electronic and magnetic states of Co and Mn atoms at the interface of the Co{sub 2}Mn{sub β}Si (CMS)/MgO (β = 0.69, 0.99, 1.15, and 1.29) magnetic tunnel junction (MTJ) by means of x-ray magnetic circular dichroism. In particular, the Mn composition (β) dependences of the Mn and Co magnetic moments were investigated. The experimental spin magnetic moments of Mn, m{sub spin}(Mn), derived from x-ray magnetic circular dichroism weakly decreased with increasing Mn composition β in going from Mn-deficient to Mn-rich CMS films. This behavior was explained by first-principles calculations based on the antisite-based site-specific formula unit (SSFU) composition model, which assumes the formation of only antisite defect, not vacancies, to accommodate off-stoichiometry. Furthermore, the experimental spin magnetic moments of Co, m{sub spin}(Co), also weakly decreased with increasing Mn composition. This behavior was consistently explained by the antisite-based SSFU model, in particular, by the decrease in the concentration of Co{sub Mn} antisites detrimental to the half-metallicity of CMS with increasing β. This finding is consistent with the higher tunnel magnetoresistance ratios which have been observed for CMS/MgO/CMS MTJs with Mn-rich CMS electrodes.

Authors:
; ; ; ;  [1];  [2]; ;  [3]; ; ;  [4]
  1. Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)
  2. Photon Factory, IMSS, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan)
  3. Research Institute of Electrical Communication, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan)
  4. Division of Electronics for Informatics, Hokkaido University, Sapporo 060-0814 (Japan)
Publication Date:
OSTI Identifier:
22410244
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 117; Journal Issue: 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONCENTRATION RATIO; COPPER COMPOUNDS; FILMS; INTERFACES; MAGNESIUM OXIDES; MAGNETIC CIRCULAR DICHROISM; MAGNETIC MOMENTS; MAGNETIC PROPERTIES; MAGNETORESISTANCE; MANGANESE SILICIDES; METALLICITY; SPIN; STOICHIOMETRY; TUNNEL EFFECT; VACANCIES; X RADIATION

Citation Formats

Singh, V. R., Verma, V. K., Ishigami, K., Shibata, G., Fujimori, A., E-mail: fujimori@wyvern.phys.s.u-tokyo.ac.jp, Koide, T., Miura, Y., Shirai, M., Ishikawa, T., Li, G.-F., and Yamamoto, M. Electronic and magnetic properties of off-stoichiometric Co{sub 2}Mn{sub β}Si/MgO interfaces studied by x-ray magnetic circular dichroism. United States: N. p., 2015. Web. doi:10.1063/1.4921538.
Singh, V. R., Verma, V. K., Ishigami, K., Shibata, G., Fujimori, A., E-mail: fujimori@wyvern.phys.s.u-tokyo.ac.jp, Koide, T., Miura, Y., Shirai, M., Ishikawa, T., Li, G.-F., & Yamamoto, M. Electronic and magnetic properties of off-stoichiometric Co{sub 2}Mn{sub β}Si/MgO interfaces studied by x-ray magnetic circular dichroism. United States. doi:10.1063/1.4921538.
Singh, V. R., Verma, V. K., Ishigami, K., Shibata, G., Fujimori, A., E-mail: fujimori@wyvern.phys.s.u-tokyo.ac.jp, Koide, T., Miura, Y., Shirai, M., Ishikawa, T., Li, G.-F., and Yamamoto, M. Thu . "Electronic and magnetic properties of off-stoichiometric Co{sub 2}Mn{sub β}Si/MgO interfaces studied by x-ray magnetic circular dichroism". United States. doi:10.1063/1.4921538.
@article{osti_22410244,
title = {Electronic and magnetic properties of off-stoichiometric Co{sub 2}Mn{sub β}Si/MgO interfaces studied by x-ray magnetic circular dichroism},
author = {Singh, V. R. and Verma, V. K. and Ishigami, K. and Shibata, G. and Fujimori, A., E-mail: fujimori@wyvern.phys.s.u-tokyo.ac.jp and Koide, T. and Miura, Y. and Shirai, M. and Ishikawa, T. and Li, G.-F. and Yamamoto, M.},
abstractNote = {We have studied the electronic and magnetic states of Co and Mn atoms at the interface of the Co{sub 2}Mn{sub β}Si (CMS)/MgO (β = 0.69, 0.99, 1.15, and 1.29) magnetic tunnel junction (MTJ) by means of x-ray magnetic circular dichroism. In particular, the Mn composition (β) dependences of the Mn and Co magnetic moments were investigated. The experimental spin magnetic moments of Mn, m{sub spin}(Mn), derived from x-ray magnetic circular dichroism weakly decreased with increasing Mn composition β in going from Mn-deficient to Mn-rich CMS films. This behavior was explained by first-principles calculations based on the antisite-based site-specific formula unit (SSFU) composition model, which assumes the formation of only antisite defect, not vacancies, to accommodate off-stoichiometry. Furthermore, the experimental spin magnetic moments of Co, m{sub spin}(Co), also weakly decreased with increasing Mn composition. This behavior was consistently explained by the antisite-based SSFU model, in particular, by the decrease in the concentration of Co{sub Mn} antisites detrimental to the half-metallicity of CMS with increasing β. This finding is consistent with the higher tunnel magnetoresistance ratios which have been observed for CMS/MgO/CMS MTJs with Mn-rich CMS electrodes.},
doi = {10.1063/1.4921538},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 20,
volume = 117,
place = {United States},
year = {2015},
month = {5}
}