Speaker
Loïc Le Guyader
(Swiss Light Source, Paul Scherrer Institut)
Description
The magnetization direction of ferromagnetic (FM) films can be pinned by coupling them to an antiferromagnet (AFM). It has been demonstrated recently [A. Kimel et al., Nature, 429, 850 (2004)] that a subpicosecond laser-excitation of an antiferromagnetic orthoferrites RFeO3, where R is a rare-earth ion, may result in ultrafast modification of the magnetic anisotropy followed by a reorientation of the antiferromagnetic spins over 90-degrees within a few picoseconds, which is much faster than a typical nanoseconds long spin precession period in a ferromagnetic material. What would be the response of an FM-layer if such a spin-reorientation in the AFM takes place in a coupled AFM-FM structure? How fast would the FM-layer reorient?
Here we report on our investigations of the laser-induced dynamics of Co spins in a Co/SmFeO3 heterostructure using X-ray magnetic circular dichroism (XMCD) and time-resolved Photoemission electron microscopy. Orientation changes of the Co-spins faster than 100 ps is observed. The possible formation of exchange springs in the SmFeO3 to prevent large orientation changes will be discussed.
This work is supported by EC FP7 [Grant No. NMP3-SL-2008-214469]
Author
Loïc Le Guyader
(Swiss Light Source, Paul Scherrer Institut)
Co-authors
Alexey Kimel
(IMM, Radboud University, Nijmegen, The Netherlands)
Andrei Kirilyuk
(IMM, Radboud University, Nijmegen, The Netherlands)
Armin Kleibert
(Swiss Light Source, Paul Scherrer Institut)
Frithjof F. Nolting
(Swiss Light Source, Paul Scherrer Institut)
Loïc Joly
(IPCMS, Strasbourg, France)
Theo Rasing
(IMM, Radboud University, Nijmegen, The Netherlands)
