Eur. Phys. J. B (2013) 86: 183
https://doi.org/10.1140/epjb/e2013-30682-6

Regular Article

The role of magnetization compensation point for efficient ultrafast control of magnetization in Gd₂₄Fe_66.5Co_9.5 alloy^*

¹ Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, Netherlands
² Ioffe Physical Technical Institute of the Russian Academy of Sciences, 194021 St. Petersburg, Russia
³ College of Science and Technology, Nihon University, 7-24-1 Funabashi, Chiba, Japan

^a e-mail: rajshekhar85@gmail.com

Received: 24 July 2012
Received in final form: 25 July 2012
Published online: 24 April 2013

Abstract

The ability of a femtosecond laser pulse to manipulate and reverse the magnetization in a ferrimagnetic Gd₂₄Fe_66.5Co_9.5 thin film was studied experimentally as a function of temperature. For a fixed energy of the laser pulse, the dynamics of magnetization showed different behavior depending on whether the sample temperature was below or above the magnetization compensation point (T_M). The conditions for full ultrafast demagnetization and magnetization reversal were easily achieved below T_M, while the same laser excitation caused just 50% demagnetization above T_M. This interesting change in magnetization dynamics is qualitatively explained in terms of effective changes in the magnitudes of magnetizations of atomic sublattices.