Laser single-shot magnetization reversal in Co1−xLux nanostructures

Abstract

The magnetic properties of $\mathrm{Pt}\text{/}{Co}_{1\ensuremath{-}x}{\mathrm{Lu}}_{x}\text{/}\mathrm{Pt}$ thin films have been investigated. For an alloy thickness of 3 nm, the saturation magnetization linearly decreases from 830 kA/m to 400 kA/m for $x$ varying between 18% and 40%, including the proximity-induced moment in platinum. Furthermore, we show that ${\mathrm{Co}}_{1\ensuremath{-}x}{\mathrm{Lu}}_{x}$ alloys 3 nm thick thin films have a perpendicular magnetic anisotropy for a concentration ranging between 25% and 40%. A single femtosecond laser shot leads to a demagnetized state with a domain size that increases with the decrease of saturation magnetization. Patterning the layer into dots leads to a single domain structure that can be fully reversed using a single laser pulse. The statistics and the origin of the nondeterministic reversal are discussed based on the atomistic model.