Influence of capping layers on CoFeB anisotropy and damping

Journal Article · Sat Sep 01 00:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4749412· OSTI ID:22089430

Natarajarathinam, A. ^[1]; Tadisina, Z. R.; Gupta, S. ^[1]; Mewes, T. ^[1]; Watts, S.; Chen, E. ^[2]

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1. Center for Materials for Information Technology (MINT Center), University of Alabama, Tuscaloosa, Alabama 35487 (United States)
2. Grandis Inc., Milpitas, California 95035 (United States)

Magnetic behavior of CoFeB at various thicknesses ranging from 2 nm to 8 nm capped with different materials, such as MgO, Ta, Ru, and V have been studied. The films were sputter-deposited and subsequently characterized by magnetometry and broadband ferromagnetic resonance (FMR). There are magnetically dead layers at the interface observed with Ru and Ta capping layers, while MgO and V have almost no effect on the magnetization of the CoFeB. As the ferromagnetic layer is made thinner, the effective magnetization decreases, indicating an interfacial perpendicular anisotropy. Particularly in the case of MgO, V/Ru, and V/Ta capping layers, interfacial perpendicular anisotropy is induced in CoFeB, and the Gilbert damping parameter is also reduced. The origin of this perpendicular magnetic anisotropy (PMA) is understood to be caused by the interface anisotropy between the free layer and the capping layer. The effect of post-deposition annealing and CoFeB thickness on the anisotropy and damping of V/Ta capped samples are reported. Doping CoFeB with vanadium (V) greatly reduced the 4{pi}M{sub s} and 4{pi}M{sub eff} values, resulting in an effective increase in the PMA.

• OSTI ID: 22089430
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 112; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
ANNEALING
BORON COMPOUNDS
COBALT COMPOUNDS
DEPOSITION
FERROMAGNETIC MATERIALS
FERROMAGNETIC RESONANCE
INTERFACES
IRON COMPOUNDS
LAYERS
MAGNESIUM OXIDES
MAGNETISM
MAGNETIZATION
RUTHENIUM
SPUTTERING
TANTALUM
THICKNESS
THIN FILMS
VANADIUM