Linear and elliptical magnetization reversal close to the Curie temperature

¹  Department of Physics, University of York - York YO10 5DD, UK, EU
²  Department of Physics, University of Konstanz - D-78457 Konstanz, Germany, EU

Corresponding author: ulrich.nowak@uni-konstanz.de

Received: 5 December 2008
Accepted: 30 March 2009

Abstract

For further improvement of magnetic information storage density and writing speed, laser-induced writing procedures have been extensively explored recently. Within the framework of the Landau-Lifshitz-Bloch equation of motion, which does not conserve the length of the magnetization vector, we investigate thermally assisted switching analytically. We show that for temperatures close to (but still below) the Curie temperature two reversal modes appear, an elliptical mode and a linear one. We calculate the coercive fields and energy barriers for both elliptical and linear switching. Investigating the dynamics of linear reversal, which is the more relevant case close to the Curie temperature, we calculate the temperature dependence of the minimal time and field needed for thermally assisted switching below and above the Curie temperature.