title: Laser-induced magnetization dynamics of lanthanide-doped permalloy thin films.
abstract: We investigate the effect of Ho, Dy, Tb, and Gd impurities on the femtosecond laser-induced magnetization dynamics of thin Permalloy films using the time-resolved magneto-optical Kerr effect. Varying the amount of Ho, Dy, Tb content from 0% to 8%, we observe a gradual change of the characteristic demagnetization time constant from approximately 60 to approximately 150 fs. In contrast, Gd concentrations up to 15% do not influence the time scale of the initial photoinduced magnetization loss. We propose a demagnetization mechanism that relies on strong magnetic inertia of the rare-earth dopant which stabilizes the ferrimagnetic ordering and thereby delays the demagnetization.
authors.affiliation: Physics Department, Universität Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Radu
authors.forename: G
authors.initials: G
authors.lastname: Woltersdorf
authors.forename: M
authors.initials: M
authors.lastname: Kiessling
authors.forename: A
authors.initials: A
authors.lastname: Melnikov
authors.forename: U
authors.initials: U
authors.lastname: Bovensiepen
authors.forename: J-U
authors.initials: JU
authors.lastname: Thiele
authors.forename: C H
authors.initials: CH
authors.lastname: Back