CONTROL OF CRYSTALLOGRAPHIC AND MAGNETIC TEXTURE IN DC-MAGNETRON SPUTTERED CO-CR ON FLEXIBLE PET SUBSTRATE

The paper reports on hard-magnetic thin films on flexible PET substrat es. The total coating stack is deposited in a roll-coater by dc-magnet ron sputtering and includes a Cr underlayer, a Co-Cr magnetic layer, a nd an SiO2 wear-resistant layer on top. The influence of various depos ition parameters on crystallographic and magnetic properties has been investigated. The magnetic anisotropy direction in Co-Cr can be change d from perpendicular to in-plane by applying a (very thin) Cr underlay er. This in-plane anisotropy is directed in the machine direction, pro bably due to an anisotropic magnetostriction. No clear relation betwee n coercivity and crystallinity or grain size is observed. The coercivi ty is mainly influenced by film thickness and substrate temperature. F or Co-Cr without Cr underlayer, an increasing temperature results in i ncreased coercivity and more distinct grains. For Co-Cr with Cr underl ayer, an increasing temperature results in decreased coercivity and le ss distinct grains. (C) 1998 Elsevier Science S.A.