Yttrium addition and annealing effect on the structural, magnetic, adhesive, and optical properties of CoFeY thin films on glass substrate

Abstract

Co60Fe20Y20 film was sputtered on glass substrate with a 10 nm to 50 nm under four annealed conditions and the structure, magnetic properties, surface energy, and optical property were examined. An amorphous structure of CoFeY films was revealed by an X-ray diffraction analyzer, suggesting that the addition of yttrium (Y) refined the grain size and the annealing temperatures were insufficient to support grain growth. The saturation magnetization (Ms) and low-frequency alternate-current magnetic susceptibility (χac) increased with the increase in the thicknesses and annealing temperatures, suggesting that the thickness effect and Y can refine grain size and induce ferromagnetic spin exchange coupling. The highest Ms and χac of Co60Fe20Y20 film were 735 emu/cm3 and 0.23 at an annealing temperature of 300 °C and 50 nm. The χac value of CoFeY film decreased significantly with the increase in measured frequency, while the maximum χac value increased significantly after heat treatment. The optimal resonance frequency (fres) corresponding to the maximum χac was 50 Hz, indicating the applicability of the film in a low-frequency range. The highest surface energy of the 50 nm was 31.84 mJ/mm2 at 300 °C, while the highest transmittance 58% was observed in as-deposited 10 nm film. The transmittance decreased with the increase in annealing temperatures and thickness. A higher thickness may inhibit photon signal transfer through the film, causing a low transmittance. Moreover, the specific properties of Co60Fe20Y20 films are compared with Co40Fe40B10Y10 films, which indicate that Co60Fe20Y20 films have high maximum χac, surface energy, and transmittance than Co40Fe40B10Y10 films.