Laser induced spin precession in highly anisotropic granular L1{sub 0} FePt

Journal Article · Mon Apr 14 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4871869· OSTI ID:22262606

Becker, J. ^[1]; Mosendz, O.; Weller, D. ^[2]; Kirilyuk, A.; Rasing, Th.; Kimel, A. ^[1]; Maan, J. C.; Christianen, P. C. M. ^[3]

---

1. Radboud University Nijmegen, Institute for Molecules and Materials, Nijmegen 6525 AJ (Netherlands)
2. HGST, a Western Digital company, 3403 Yerba Buena Road, San Jose, California 95135 (United States)
3. High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen (Netherlands)

The dynamic magnetic properties of a highly anisotropic, granular L1{sub 0} FePt thin film in magnetic fields up to 7 T are investigated using time-resolved magneto-optical Kerr effect measurements. We find that ultrashort laser pulses induce coherent spin precession in the granular FePt sample. Frequencies of spin precession up to over 400 GHz are observed, which are strongly field and temperature dependent. The high frequencies can be ascribed to the high value of the magnetocrystalline anisotropy constant K{sub u} leading to large anisotropy fields H{sub a} of up to 10.7 T at 170 K. A Gilbert damping parameter of α ∼ 0.1 was derived from the lifetimes of the oscillations.

• OSTI ID: 22262606
• Journal Information: Applied Physics Letters, Vol. 104, Issue 15; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
KERR EFFECT
LASERS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
PRECESSION
SPIN
TEMPERATURE DEPENDENCE
THIN FILMS