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Why are spin wave excitations all important in nanoscale magnetism?
Author(s) -
Baberschke Klaus
Publication year - 2008
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200776452
Subject(s) - magnon , magnetism , condensed matter physics , spin wave , ferromagnetism , nanomagnet , dissipative system , curie temperature , spin (aerodynamics) , relaxation (psychology) , physics , quantum mechanics , magnetization , magnetic field , thermodynamics , psychology , social psychology
For a proper interpretation of magnetic phenomena in low dimensional magnets, higher order spin wave excitations are more important than in bulk magnetism. Three different types of experiments will be discussed: (i) In a so‐called trilayer , two ferromagnetic films are coupled via a nonmagnetic spacer: FM1/ NM/FM2. The individual Curie temperatures can be shif‐ ted by 50 K or 100 K, just by tuning the NM thickness. This is impossible in 3D. (ii) Spin‐wave excitations are the major route to understanding the T‐dependence of the interlayer exchange coupling (IEC). (iii) The standard Gilbert damping is insufficient to describe the spin dynamics in nanomagnets. Magnon–magnon scattering, a reversible process in the magnetic subsystem, must first be disentangled in the spin dynamics, before determining the dissipative relaxation into the thermal bath. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)