Spin-lattice relaxation phenomena in manganite thin filmsM. C. Weber1, B. Hillebrands1, V. Moshnyaga2 and K. Samwer2
1 Fachbereich Physik und Forschungsschwerpunkt MINAS Technische Universität Kaiserslautern - Erwin-Schrödinger-Str. 56 67663 Kaiserslautern, Germany
2 I. Physikalisches Institut, Universität Göttingen Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
received 21 July 2005; accepted in final form 15 November 2005
published online 2 December 2005
Time-resolved magneto-optics was used to study spin-lattice relaxation dynamics in thin epitaxial films. Two distinct recovery regimes of the ferromagnetic order can be resolved upon photoexcitation, which manifest themselves by two different relaxation times. A pump pulse energy-independent spin-lattice relaxation time can be deduced. Due to a weak spin-orbit coupling in manganites this spin-lattice relaxation time is much longer than in ferromagnetic metals. Heat flow into the substrate sets the ultimate recovery speed of the ferromagnetic order and allows for a determination of heat diffusion properties of manganite films.
78.47.+p - Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter.
75.70.-i - Magnetic properties of thin films, surfaces, and interfaces.
75.40.Gb - Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.).
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