Magnetic and all-optical switching properties of amorphous<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Tb</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mi>Co</mml:mi><mml:mrow><mml:mn>100</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>alloys
Agne Ciuciulkaite, Kshiti Mishra, Marcos V. Moro, Ioan-Augustin Chioar, Richard M. Rowan-Robinson, Sergii Parchenko, Armin Kleibert, B. Lindgren, Gabriella Andersson, C. S. Davies, A. V. Kimel, Marco Berritta, Peter M. Oppeneer, A. Kirilyuk, Vassilios Kapaklis
Abstract
Amorphous ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}$ magnetic alloys exhibit a list of intriguing properties, such as perpendicular magnetic anisotropy, high magneto-optical activity, and magnetization switching using ultrashort optical pulses. Varying the Tb:Co ratio in these alloys allows for tuning properties such as the saturation magnetic moment, coercive field, and the performance of light-induced magnetization switching. In this paper, we investigate the magnetic, optical, and magneto-optical properties of various ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}$ thin-film alloy compositions. We report on the effect the choice of different seeding layers has on the structural and magnetic properties of ${\mathrm{Tb}}_{x}{\mathrm{Co}}_{100\ensuremath{-}x}$ layers. We also demonstrate that for a range of alloys, deposited on fused silica substrates, with Tb content of 24--30 at. $%$, helicity-dependent all-optical switching of magnetization can be achieved, albeit in a multishot framework. We explain this property to arise from the helicity-dependent laser-induced magnetization on the Co sublattice due to the inverse Faraday effect. Our paper provides an insight into material aspects for future potential hybrid magnetoplasmonic TbCo-based architectures.