Laser annealing and selective magnetization of manganese-aluminum alloys

Abstract

MnxAl1−x alloys (0.5⩽x⩽0.6) and related materials feature a phase transition from an essentially nonmagnetic state to a state having large magnetization. The transition is generally induced by appropriate conventional annealing. We demonstrate that a modest-power laser is also capable of bulk annealing. More importantly, focused laser radiation can be used to anneal preselected portions of a sample, thus introducing small, hard magnetic regions into an otherwise nonmagnetic host. Tailoring of magnetic devices and information storage are potential areas of application.