Zero-field spin-transfer oscillators combining in-plane and out-of-plane magnetized layers

• DOI: 10.7567/apex.7.043001
• Publication Date: 2014-04-11T18:08:29Z
• Authors: Ciarán Fowley; Volker Sluka; Kerstin Bernert; Jürgen Lindner; Jürgen Fassbender; William H. Rippard; Matthew R. Pufall; Stephen E. Russek; Alina M. Deac

Excited magnetization dynamics in a spin-valve device consisting of an in-plane polarizer and an out-of-plane free layer were studied numerically. In the case where the free layer is assumed to lack any in-plane anisotropy components, a finite external field is required to generate steady-state dynamics, in agreement with previous reports. We demonstrate that this constraint can be removed and precession can be stabilized in zero applied field by introducing an additional in-plane anisotropy axis. Moreover, the in-plane anisotropy offers an additional degree of freedom for tuning the frequency response of the device.