Cobalt island arrays with in-plane anisotropy electrodeposited in highly ordered alumite

Highly ordered ferromagnetic Co arrays were fabricated by electrodeposition into the pores of porous alumina surfaces with hexagonally ordered areas up to 100 μm². The pore diameter varied between 25-60 nm, while pore-to-pore distance was 110 nm. Various voltage and current waveforms were employed to control the nucleation, growth and consequently magnetic properties of the Co array. Arrays with perpendicular and longitudinal anisotropy were produced by a judicious choice of deposition parameters and suitable template conditioning. Magnetic properties were studied as a function of the nano-particle length (5-500 nm). Long particles exhibit perpendicular anisotropy with coercivity up to 2 kOe and high squareness in the perpendicular direction; short particles with longitudinal anisotropy exhibit an in-plane coercivity of up to 700 Oe and squareness 0.35