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Title: Structural and magnetic properties of epitaxial Heusler alloy Fe{sub 2}Cr{sub 0.5}Co{sub 0.5}Si

This paper reports the study of structural and magnetic properties of Heusler alloy Fe{sub 2}Cr{sub 0.5}Co{sub 0.5}Si (FCCS) thin film and its tunnel magnetoresistance (TMR) effect. The smooth quaternary Heusler alloy FCCS film with surface roughness of rms value of 0.25 nm measured by atomic force microscopy and partial L2{sub 1} phase was obtained by magnetron sputtering at room temperature followed by in-situ annealing at 400 °C. The saturation magnetization and coercivity of FCCS are 410 emu/cm{sup 3} and 20 Oe, respectively. The magnetic tunnel junctions (MTJs) using FCCS as free layer were studied in detail as a function of post-annealing temperature. A TMR ratio of 15.6% has been achieved with 300 °C post-annealing. This is about twice the highest TMR ratio obtained in MTJs using Fe{sub 2}CrSi. The enhancement of TMR ratio can be attributed to the successful tuning of the Fermi level of Fe{sub 2}CrSi close to the center of the minority band gap by Co-doping.
Authors:
 [1] ;  [2] ; ; ;  [3] ; ;  [1]
  1. Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583 (Singapore)
  2. (A-STAR), 5 Engineering Drive 1, Singapore 117608 (Singapore)
  3. Data Storage Institute, Agency for Science, Technology and Research (A-STAR), 5 Engineering Drive 1, Singapore 117608 (Singapore)
Publication Date:
OSTI Identifier:
22273599
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; 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; ANNEALING; ATOMIC FORCE MICROSCOPY; CHROMIUM COMPOUNDS; COBALT SILICIDES; COERCIVE FORCE; EPITAXY; FCC LATTICES; FERMI LEVEL; HEUSLER ALLOYS; IRON COMPOUNDS; MAGNETIC PROPERTIES; MAGNETIZATION; MAGNETORESISTANCE; ROUGHNESS; SUPERCONDUCTING JUNCTIONS; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; TUNNEL EFFECT