Ultrafast actuation of Ni-Mn-Ga micropillars by pulsed magnetic field

摘要

We report on the pulsed magnetic field actuation of single crystalline Ni-Mn-Ga cuboid micropillars with dimensions of 40 x 45 x 120 mu m(3), created by focused ion beam milling followed by electrochemical etching. Based on the experimental and modelled results, we differentiate between type I and type II twin boundary motion in the micropillar, which display about an order difference in actuation velocities. Magnetically-induced reorientation of a micropillar was obtained in less than 5 mu s by type H twin boundary motion. Our results suggest the possibility of fabrication of magnetic shape memory microdevices with working frequencies up to 100 kHz. (C) 2018 Published by Elsevier Ltd.