FMR Linewidth divergence in V$_{2}$O$_{3}$/Ni bilayers*

The effects of stress on the magnetic properties of ferromagnetic thin films are dramatic when the ferromagnets are in proximity with materials undergoing structural phase transitions (SPT) [1]. Here we report on Ferromagnetic Resonance (FMR) measurements on V$_{2}$O$_{3}$/Ni bilayers across the SPT of V$_{2}$O$_{3}$. The SPT occurs on V$_{2}$O$_{3}$ at 160 K from a metallic/rhombohedral to an insulating/monoclinic phase. Our results reveal a rotation of the anisotropy axis in Nickel films when cooled below the SPT of V$_{2}$O$_{3}$. The obtained anisotropy axis will be compared to the underlying structural morphology obtained from x-ray diffraction. More interestingly, the FMR linewidth as a function of the temperature shows a divergence across the SPT. This suggests a breakdown of the uniform precession of the Ni magnetization caused by the induced strain across the SPT. Discussion among linewidth-broadening mechanisms will be addressed. \\[4pt] [1] J. de la Venta, S. Wang, J. G. Ramirez, and I. K. Schuller, Appl. Phys. Lett. 102, 122404 (2013).