Switching time in laser pulse heat-assisted magnetic recording using L1{sub 0}-FePt nanoparticles

Journal Article · Tue Apr 07 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4916258· OSTI ID:22399384

Weller, D.; Parker, G. J. ^[1]

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1. HGST, a Western Digital Company, 3403 Yerba Buena Road, San Jose, California 95135 (United States)

Atomistic spin model simulations using Langevin dynamics are performed to study the factors that determine the thermomagnetic recording time window in FePt media. The onset of thermomagnetic writing occurs at a temperature T{sub o} larger than the Curie temperature T{sub c} as a result of the finite time of relaxation of the magnetization by the linear reversal mode. The Bloch relaxation rate of magnetization growth during cooling below T{sub c} is independent on the write field, provided the field is stronger than some threshold value. Application of a strong write field reduces switching time through better spin alignment in the paramagnetic regime. Finite size effects on the probability distribution of freezing temperatures T{sub f} and the free energy provide insight on the thermomagnetic reversal mechanism. Constraints on the “pulse-mode” of recording when the head field reverses direction during cooling are also considered.

• OSTI ID: 22399384
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 13; Other Information: (c) 2015 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
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPUTERIZED SIMULATION
COOLING
CURIE POINT
ELECTROMAGNETIC PULSES
FREE ENERGY
FREEZING
HEAT
INTERMETALLIC COMPOUNDS
IRON
MAGNETIZATION
NANOPARTICLES
PARAMAGNETISM
PLATINUM
RELAXATION
SPIN
THERMOMAGNETISM