Influence of film thickness on the electrical and magnetic properties of Co–Fe–Al–O films

Abstract

Influence of film thickness (t) on the electrical and magnetic properties of Co-Fe-Al-O films has been systematically investigated via means of vibrating sample magnetometry (VSM), permeability spectra and magneto-optical Kerr effect (MOKE). It is found that the electrical resistivity (ρ) decreases as the film thickness increases; ρ = 412.5 µΩcm for the t = 600 nm sample decreases to ρ = 368.2 µΩcm for the t = 1200 nm sample. The coercive force, measured along the easy-axis direction, decreases as the film thickness increases. Interestingly, along the hard-axis magnetization direction, the magnetic hysteresis loop is reversed and the coercive force is negative for the t = 600 and 800 nm samples. However, this peculiar feature disappears as t reaches 1200 nm, which is probably attributed to the microstructural change with respect to changes of film thickness. At a frequency of 1GHz, the hard-axis effective permeability decreases from 1252 to 1000 as the film thickness increases from 600 to 1200 nm, respectively. The VSM and MOKE results reveal an increase in magnetic anisotropy in the near-surface region of the film.

The effect of Al2 O3 additive on the microstructure and magnetic properties of Co75 Cr13 Pt12 /Cr thin films

“…The Co‐based alloy films have widely overcome the use of nanocomposites as they show exclusive properties such as high coercivity and low intergranular coupling. Hence, they are one of the most promising candidates for the ultrahigh density recording media . There are currently several methods to obtain high coercivity through magnetic‐grain isolation.…”