Annealing-induced Structural and Magnetic Modifications in SmCo5 Thin Films

Due to its largest uniaxial magneto crystalline anisotropy, SmCo5 is an excellent material for ultra-high density magnetic recording media and other hard magnetic applications. In this work, a SmCo5 thin film with a thickness ~ 500 Å was deposited on a Si(100) substrate to investigate its structural and magnetic properties. The internal structure of the sample, including film thickness, electron density, and roughness was precisely characterized by the X-ray reflectivity (XRR) study. The magnetic properties of the sample were studied using the Magneto-Optical Kerr Effect (MOKE) study. There is no in-plane magnetic anisotropy in the films as confirmed by in-plane polar MOKE loops. The sample was subsequently annealed under high vacuum at 400 ℃ to tailor its magnetic properties. A significant increase in the coercivity of the film was observed due to annealing. XRR analysis of the annealed sample shows noticeable structural modifications compared to the pristine sample. The structural changes are responsible for the observed modifications in the magnetic properties of the annealed sample.