Stress-coefficient of magnetoelastic anisotropy in flexible Fe, Co and Ni thin films

Abstract

Magnetoelastic anisotropy is one of the most essential and fundamental characteristics in the magnetic anisotropy, which holds the core application and broad prospects in advanced flexible magnetic devices. Here, we determined the stress-coefficient of magnetoelastic anisotropy of Fe, Co and Ni thin films deposited on flexible polyvinylidene fluoride (PVDF) substrate. Owing to an anisotropic thermal expansion of PVDF, a uniaxial stress can be effectively generated and transferred to the magnetic films in-situ by changing the temperature. The magnetic anisotropy constants at different compressive stresses were quantitatively investigated with anisotropic magnetoresistance (AMR). Through fitting the AMR curves at different compressive stresses, the stress-coefficient of magnetoelastic anisotropy of Fe, Co and Ni thin films were determined to be (6.31±0.19)×103 erg cm−3 GPa−1, (2.71±0.13)×104 erg cm−3 GPa−1 and (2.46±0.19)×105 erg cm−3 GPa−1, respectively. These values are basic magnetic parameter for magnetic elements, which are helpful for evaluating the performance of magnetic devices under flexible/stretchable conditions.