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

Journal Article · Wed May 07 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4852117· OSTI ID:22273599

Wang, Yu-Pu ^[1]; Han, Gu-Chang; Qiu, Jinjun; Yap, Qi-Jia ^[2]; Lu, Hui; Teo, Kie-Leong ^[1]

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1. Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583 (Singapore)
2. Data Storage Institute, Agency for Science, Technology and Research (A-STAR), 5 Engineering Drive 1, Singapore 117608 (Singapore)

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.

• OSTI ID: 22273599
• Journal Information: Journal of Applied Physics, Vol. 115, 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); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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