The dependence of the microstructure and magnetic properties of CoNiCr/Cr thin films on the substrate temperature

Thin CoNiCr/Cr films (candidates for longitudinal recording media) were deposited on Corning 7059 glass substrate by RF diode sputtering. The CoNiCr layer thickness was fixed at 40 nm; the Cr layer thickness, d_Cr, ranged between 60 and 400 nm. At d_Cr=170 nm, when the substrate temperature before deposition, T_s, was set below 100°C, both the Cr underlayer and the CoNiCr layer were more or less randomly oriented. When specimens were deposited at T_s⩾200°C, the Cr layer was strongly {100} textured and the CoNiCr layer exhibited a strongly preferred texture. This CoNiCr texture is epitaxially favored by the Cr {100} texture. With increasing d_Cr the Cr {110} texture increased and the CoNiCr texture decreased. The grain size increased with T_s and d_Cr. In-plane coercivity, H_c, initially increased with T_s to peak at T_s=200°C. As T_s was increased further from 200 to 260°C, H_c decreased. The squareness and saturation magnetization were not sensitive to T_s