  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.
