Investigating the effect of thickness on the structural and magnetic properties of carbon thin film

The effect of thickness on the magnetic property of amorphous carbon thin film is reported. Three different carbon thin films are deposited by varying the deposition time keeping all the parameters fixed. Microstructural characterization carried out using Grazing Incidence X-ray Diffraction, and Raman spectroscopy indicates the films are amorphous with the presence of molecular units whose edges are bonded with sp3 hybridized atoms. The chemical characterization performed using X-ray photoelectron spectroscopy (XPS), and X-ray absorption near-edge spectroscopy (XANES) indicates that the sp3 fraction and the conjugation between the sp2 hybridized atoms increases with increasing film thickness. The magnetic property studied using SQUID-VSM reveals the existence of weak ferromagnetic coupling between the unpaired spins present at sp2 sites. The saturation magnetization of the film decreases with increasing thickness. However, estimated magnetic moment/area reveals that there lies a threshold of thickness beyond which the insignificant enhancement in the magnetic moment of the film occurs. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

The effect of thickness on the magnetic property of amorphous carbon thin film is investigated. It is found that the thickness variation affects the microstructure and chemical characteristics of the films, leading to changes in their magnetic properties. The presence of weak ferromagnetic coupling between unpaired spins at sp2 sites is observed, and the saturation magnetization of the film decreases with increasing thickness.