Ion deposited nanoscale permalloy and Co films generated from laser excitation

Abstract

A modified pulsed laser deposition system has been used to deposit permalloy and Co films from ions generated due to the impact of 248 nm excimer laser pulses. A synchronously pulsed magnetic field coil with a wide entrance throat and a tapered bore in conjunction with a set of permanent magnets has been used to capture and concentrate the ion and electron beam flux under vacuum conditions onto the substrates. Co and other films such as diamond like carbon (DLC) are strongly adherent when deposited onto even room temperature substrates. Permalloy films deposited onto Si (111) substrates with thicknesses from 10 to 50 nm exhibit anisotropic magnetoresistance of approximately 2% for magnetic fields applied in-plane parallel versus perpendicular to the current direction. Over 1 order of magnitude intensity modulation has been observed in x-ray reflectivity measurements for Co films, 7–15 nm thickness, deposited onto R-plane sapphire substrates and onto Si (111) substrates. In contrast to this Co films simultaneously deposited onto A-plane sapphire substrates hardly exhibited x-ray reflectivity fringes indicating a large surface roughness. Similarly DLC films deposited onto (111) Si substrates exhibited order of magnitude intensity modulations indicating a very small surface roughness. Scanning electron microscope measurements indicated smooth films were obtained with no discernible particulates.