Single-pulse all-optical partial switching in amorphous Dy_xCo_1?x and Tb_xCo_1?x with random anisotropy

Repeated uniform switching of the magnetization thin films ferrimagnetic amorphous Gd x (FeCo) 1?x in response to single fast laser pulses is well established. Here, we report unusual toggle sperimagnetic Dy Co and Tb with ? 0.25 irradiated 200 fs 800 nm light. The samples have strong local random anisotropy due non-S state rare earth. compensation temperature ?180 K, their Curie ?500 K. They are largely switched by first pulse, subsequent lead partial re-switching a decreasing amount area, granular structure submicrometer regions unswitched material. Individual about 700 size observed around edge spots where fluence at threshold for switching. Results discussed terms model ratio exchange dependent.