Effect of Substrate Temperature on Properties of BaM/Pd-Pt Double Layered Thin Film

Abstract

Magnetic and crystallographic properties of barium ferrite (BaM) thin films, deposited onto Pt, Pd, and Pd-Pt underlayer at the different substrate temperature (T_s) of 400 to 600°C have been studied. The thickness of underlayer is about 20 nm and the thickness of barium ferrite film is 30 nm. From x-ray diffraction patterns, all of the BaM films grown on the three kinds of underlayer show its c-axis orientation perpendicular to the films plane. It is found that the coercivity values in perpendicular direction (Hc_perp) of the BaM/Pd-Pt films are higher than those of the BaM films deposited on Pd and Pt underlayer. Substrate temperature Ts for crystallization of BaM was reduced from 600°C to 450°C. The Hc_perpof 2.1 kOe for BaM (30nm)/Pd-Pt (20nm) film can be achieved with c-axis orientation. Pd-Pt underlayer not only improve the value of c-axis dispersion angle Δθ₅₀ and perpendicular coercivity Hc_perpbut also effective to reduce grain size of BaM thin film.