Field-induced domain wall motion of amorphous [CoSiB/Pt]{sub N} multilayers with perpendicular anisotropy

Journal Article · Wed May 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4876259· OSTI ID:22275570

Choi, Y. H.; Lee, K. J.; Yoon, J. B.; Cho, J. H.; You, C. -Y. ^[1]; Kim, T. W. ^[2]

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1. Department of Physics, Inha University, Incheon 402-751 (Korea, Republic of)
2. Department of Advanced Materials Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)

Amorphous CoSiB/Pt multilayer is a perpendicular magnetic anisotropy material to achieve high squareness, low coercivity, strong anisotropy, and smooth domain wall (DW) motion, because of the smoother interface compared with crystalline multilayers. For [CoSiB(6 Å)/Pt (14 Å)]{sub N} multilayers with N = 3, 6, and 9, we studied the field-induced DW dynamics. The effective anisotropy constant K{sub 1}{sup eff} is 1.5 × 10{sup 6} erg/cm{sup 3} for all the N values, and the linear increment of coercive field H{sub c} with N gives constant exchange coupling J. By analyzing the field dependence of DW images at room temperature, a clear creep motion with the exponent μ = 1/4 could be observed. Even though the pinning field H{sub dep} slightly increases with N, the pinning potential energy U{sub c} is constant (=35 k{sub B}T) for all the N values. These results imply that the amorphous [CoSiB/Pt]{sub N} multilayers are inherently homogeneous compared to crystalline multilayers. For N ≤ 6, the pinning site density ρ{sub pin} is less than 1000/μm{sup 2}, which is about 1 pinning site per the typical device junction size of 30 × 30 nm{sup 2}. Also, the exchange stiffness constant A{sub ex} is obtained to be 0.48 × 10{sup −6} erg/cm, and the domain wall width is expected to be smaller than 5.5 nm. These results may be applicable for spin-transfer-torque magnetic random access memory and DW logic device applications.

• OSTI ID: 22275570
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 18; 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
ANISOTROPY
COBALT COMPOUNDS
COERCIVE FORCE
COMPARATIVE EVALUATIONS
COUPLING
CREEP
DOMAIN STRUCTURE
ELECTRIC CONTACTS
FLEXIBILITY
INTERFACES
LAYERS
PLATINUM
POTENTIAL ENERGY
SEMICONDUCTOR JUNCTIONS
SILICON BORIDES
TEMPERATURE RANGE 0273-0400 K