Nanomechanical Measurements of Magnetostriction and Magnetic Anisotropy in (Ga,Mn)As

A (Ga,Mn)As nanoelectromechanical resonator is used to obtain the first direct measurement of magnetostriction in a dilute magnetic semiconductor. Field-dependent magnetoelastic stress induces shifts in resonance frequency that can be discerned with a high resolution electromechanical transduction scheme. By monitoring the field dependence, the magnetostriction and anisotropy field constants can be simultaneously mapped over a wide range of temperatures. These results, when compared with theoretical predictions, appear to provide insight into a unique form of magnetoelastic behavior mediated by holes.