Magnetoimpedance study of nickel incorporated diamond like carbon thin films

Abstract

The present work aims to investigate the magnetoimpedance (MI) behaviour of electrodeposited nickel incorporated carbon (Ni-C) composite thin films of varying nickel content. Ni-C thin films were synthesized by electrodeposition method at room temperature with low voltage. Low nickel content thin films exhibited diamond-like carbon (Ni-DLC) phase. Considering the variation of magnetoimpedance due to change in transverse magnetic permeability of Ni-C thin films, magnetoimpedance measurements were performed with frequency by applying dc magnetic field in the plane of the film in the range of-1000 Oe < H < 1000 Oe. MI measurements were carried out, by passing alternating current of 1 mA through the samples perpendicular to the magnetic field, at room temperature within a low excitation frequency (up to 100 kHz) range. Magnetoimpedance peaks were observed at 9 kHz in each thin film. Variations in the intensity of MI peaks with magnetic field were also observed. Maximum MI ratio achieved for our samples was 123%, while Ni-DLC thin film showed an MI of 110%. The values of maximum magnetoimpedance of the films were found to change with nickel content in the Ni-C thin films.