Mechanical manipulation of magnetic domains in continuous and patterned magnetostrictive FeGa thin films

The controlled and reversible switching of magnetic domains using static electric fields has been previously demonstrated via magneto-electric (ME) coupling in a multiferroic system [T. Brintlinger, Nano Lett. 10, 1219(2010)]. In these systems, enhanced magnetostriction allows for magnetic switching in response to an electrically induced deformation. Here we demonstrate the nature of magnetic switching using mechanical stress alone. Magnetostrictive iron-gallium (Fe$_{\mathrm{70}}$Ga$_{\mathrm{30}})$ thin films are deposited on flexible free-standing membranes, and patterned to square arrays. Using a mechanically manipulated tip a strain is directly applied to the film. We observe the resulting magnetization dynamics using Lorentz-force transmission electron microscopy (LTEM). The varied hysteretic behaviors under applied magnetic and strain fields will be presented for both continuous and patterned films.