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

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.
Authors:
 [1] ; ;  [2]
  1. Department of Materials Science and Technology, University of Crete, P.O. Box 2208, 71003 Heraklion (Greece)
  2. HGST, a Western Digital Company, 3403 Yerba Buena Road, San Jose, California 95135 (United States)
Publication Date:
OSTI Identifier:
22399384
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 13; Other Information: (c) 2015 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; 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