skip to main content

Title: Interfacial electronic structure-modulated magnetic anisotropy in Ta/CoFeB/MgO/Ta multilayers

We have observed several unexpected phenomena when a trace amount of Fe atoms is deposited onto the CoFeB/MgO interface in Ta/CoFeB/MgO/Ta multilayers. With the nominal thickness of the introduced Fe atoms (t{sub Fe}) varying from 0 to 0.1 Å, the effective magnetic anisotropy energy (K{sub eff}) of annealed multilayers is remarkably enhanced from 1.28 × 10{sup 6 }erg/cm{sup 3} to 2.14 × 10{sup 6 }erg/cm{sup 3}. As t{sub Fe} further increasing, the K{sub eff} decreases and even becomes negative when t{sub Fe} > 1 Å, indicating the change from perpendicular magnetic anisotropy to in-plane magnetic anisotropy. The analysis by X-ray photoelectron spectrometer reveals that the Fe atoms at annealed CoFeB/MgO interface show different electronic structures as t{sub Fe} increasing, which combine with O atoms to form FeO{sub x} (x < 1), Fe{sub 2}O{sub 3}, and Fe{sub 3}O{sub 4}, respectively, leading to modulation of Fe 3d-O 2p orbital hybridization and thus the K{sub eff}. On the other hand, we find that the introduction of Fe atoms also helps to reduce the multilayers' magnetic damping.
Authors:
; ; ; ; ;  [1] ;  [2] ;  [3]
  1. Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)
  2. SKLSM, Institute of Semiconductors, CAS, P. O. Box 912, Beijing 100083 (China)
  3. Analytical and Testing Center, Beijing Normal University, Beijing 100875 (China)
Publication Date:
OSTI Identifier:
22311022
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; ANNEALING; ATOMS; BORON COMPOUNDS; COBALT COMPOUNDS; ELECTRONIC STRUCTURE; INTERFACES; IRON COMPOUNDS; IRON OXIDES; LAYERS; MAGNESIUM OXIDES; MAGNETIC PROPERTIES; MODULATION; TANTALUM; TERNARY ALLOY SYSTEMS; TRACE AMOUNTS; X-RAY PHOTOELECTRON SPECTROSCOPY