Temperature dependent anisotropy and elastic effects in ferromagnetic nanowire arrays

Temperature dependent Ferromagnetic Resonance measurements performed as a function of diameter on Nickel nanowire arrays reveal several interesting features in these systems. With diameter decrease from 100 nm to 15 nm, a transition induced by surface anisotropy increase is observed at 50 nm in easy axis orientation from parallel to perpendicular with respect to individual nanowire geometric axis. Analysis of resonance field $H_{res}$ temperature variation (between liquid Helium and room temperature) reveals underlying strong magneto-elastic effects in small and large diameter nanowire arrays with potential applications in recording and spintronics.