N ion implantation into Fe and Co films using plasma based ion implantation

抄録

Fe and Co films are prepared on glass substrates by DC magnetron sputtering and N ion implantation is carried out by a bipolar-type plasma based ion implantation (PBII) technique. Some samples are annealed at 150℃ in vacuum after N ion implantation. The structural and compositional changes are examined by thin film X-ray diffraction (XRD) measurements, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The changes of magnetic properties are also examined by vibrating sample magnetometer (VSM). It is found that surface morphology is not changed significantly by N ion implantation and subsequently annealing as far as SEM observation, although N content is surely increased in the both films. XRD measurements reveal that nitride phases, ε-Fe_3-xN and γ-Co₃N, may be formed by N implantation. The results of VSM measurements indicate that the saturation magnetization of Fe films are slightly increased by N ion implantation. However, the saturation magnetization of Co films are decreased. After annealing at 150℃, the magnetic properties are deteriorated significantly for the both samples.