Magnetomechanical torques in small magnetic cantilevers

Abstract

We study the dynamics of small magnetic cantilevers, made from either Si covered by a magnetic film or entirely ferromagnetic materials. The magnetomechanical torques cause line splittings in ferromagnetic resonance spectra and magnetization reversal facilitated by mechanical degrees of freedom. We show that the magnetomechanical torques can extend the limits of detecting and exciting motion at the nanoscale. The "nanomotor" described here effectively transforms rf magnetic fields into mechanical oscillations. We furthermore propose to integrate mechanical oscillators into magneto-electronic devices that make use of current-induced spin-transfer torques. This opens new possibilities for electric transducers of nanomechanical motion. © 2006 The Japan Society of Applied Physics.