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.