Laser-induced transient strengthening of coupling in L10-FePt/FeNi exchange-spring film. (18th March 2015)

• Record Type: Journal Article
• Authors: Chen, Zhifeng; Li, Shufa; Lai, Tianshu
• Is Part Of: Journal of physics. Volume 48:Number 14(2015)
• Publication Date: 2015-03-18
• Subjects: exchange-coupled composite -- coupling evolution -- time-delayed loop -- pump-probe; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/48/14/145002
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Laser-induced evolution of the coupling state in a perpendicular exchange-spring L 10 -FePt/FeNi bilayer film is studied via time-delayed magneto-optical polar Kerr loops. A transient strengthening process of the coupling is found to occur simultaneously with significant reduction of the hard-phase coercivity at ~50 ps after the ultrafast demagnetization. Analysis of the time-dependent magnetization components and the micromagnetic calculation demonstrate that this delayed coupling-strengthening phenomenon originates from the opposite laser-modulation effects respectively on the hard and soft magnetic phases, in which the laser-induced transient reduction of the magnetic anisotropy in FePt phase plays the most important role.