講演情報
[15p-P07-54]Observation of all-optical switching in Gd/Co ferrimagnetic multilayers by a femtosecond laser pulse
〇Songtian Li1, Ryunosuke Takahashi2, Hiroki Wadati2, Ye Du1, Seiji Sakai1 (1.QST, 2.University of Hyogo)
キーワード：
All-optical switching (AOS)、Gd/Co、Ferrimagnet
Development of new high-speed magnetization reversal technology is essential for further increasing the speed and energy efficiency of nonvolatile magnetic memories. In recent years, all-optical switching (AOS) using ultrashort pulse laser has attracted extensive attention due to its potential for realizing ultrafast magnetic memory with speed order of picoseconds and low energy consumption. Until now, research on AOS has been focused on the ferrimagnetic GdFeCo alloy, but this alloy has problems such as difficulty in controlling the composition-dependent AOS properties and low spin polarization, which harm its application to AOS memory. The development of novel materials capable of AOS is thus anticipated. In this study, we report our recent research activities on achieving AOS in an artificial ferrimagnetic Gd/Co multilayers as novel candidate material for AOS memory applications.
Multilayer thin films consisting of Ta(3 nm)/Pt(3 nm)/Co(0.8 nm)/Gd(3 nm)/Pt(3 nm) with perpendicular magnetic anisotropy were prepared on a thermally oxidized silicon substrates by magnetron sputtering. The AOS experiment was performed using an ultrashort pulse laser with pulse width of 280 fs and wavelength of 1050 nm. The change of the magnetic state before and after the irradiation of the pulse laser was taken by magneto-optical Kerr effect (MOKE) microscope. A perfect AOS was achieved in Gd/Co ferrimagnetic multilayers. The energy density dependence of AOS and possible application to AOS magnetic memory will be discussed in detail.
Multilayer thin films consisting of Ta(3 nm)/Pt(3 nm)/Co(0.8 nm)/Gd(3 nm)/Pt(3 nm) with perpendicular magnetic anisotropy were prepared on a thermally oxidized silicon substrates by magnetron sputtering. The AOS experiment was performed using an ultrashort pulse laser with pulse width of 280 fs and wavelength of 1050 nm. The change of the magnetic state before and after the irradiation of the pulse laser was taken by magneto-optical Kerr effect (MOKE) microscope. A perfect AOS was achieved in Gd/Co ferrimagnetic multilayers. The energy density dependence of AOS and possible application to AOS magnetic memory will be discussed in detail.