Tailoring Magnetic Properties and Suppressing Anisotropy in Permalloy Films by Deposition in a Rotating Magnetic Field

We investigate the optimal deposition conditions for permalloy (Ni₈₁Fe{}₁₉$) thin films fabricated via magnetron sputtering to achieve soft magnetic films for magnetoresistive sensing applications. The films are grown with different deposition techniques such as sputtering and molecular-beam epitaxy and parameters, including varying inert gas pressure and deposition power, and with different magnetic fields applied during the growth. Our approach enables sputtering of permalloy films with low coercivity while keeping high anisotropic magnetoresistance values. We develop a robust method to characterize the intrinsic magnetic anisotropy of the films that is not dominated by local defects and we demonstrate the possibility of magnetic anisotropy suppression via implementing a rotating magnetic field during sputtering.