紫外線照射および熱キュア処理した潤滑膜形成磁気ディスクの原子間力顕微鏡およびボールオンディスク試験による表面評価

摘要

近年，磁気ディスク装置について，ますます大容量化の要求が高まり高密度記録，低価格化が実現され，急速に発展している。更なる高密度記録化を実現させるためには，磁気ディスクと磁気ヘッドのすきまを小さくすることが検討されている。そのためには保護膜厚の低減が欠かせないが，磁気ヘッドと磁気ディスクの接触による耐久性を維持する必要がある。そこで，磁気ヘッドの磁気ディスクへの接触による極表面層への影響，変化といったトライボロジー特性が磁気ディスクの信頼性向上に対して重要な役割をはたしている。%To improve the durability of magnetic disk and head interfaces, various treated Z-tetraol lubricants are coated on diamond-like carbon (DLC) films used to protect magnetic disks. In this study, ultraviolet (UV) irradiation and thermal curing are performed on a Z-tetraol lubricant, and their effect on the adhesion and repairability of the DLC protective film is evaluated by the nanoindentation and force modulation by atomic force microscopy (AFM). Then, to evaluate the durability of treated magnetic disks coated with lubricant, ball-on-disk friction test were performed. The friction coefficients of magnetic disks treated by 5 min UV irradiation are stable over time, and friction damages is also less than that observed for disks treated by thermal curing. These superior properties of UV-irradiated disks are consistent with nanotribological results evaluated by AFM and are due to strong adhesion and high repairability. Very small areas of damage formed by friction can be estimated by nanometer-scale changes of the surface profile, current distribution and the friction distribution evaluated by AFM force modulation. It was observed that the lubricant on protruding areas was removed, resulting in increased wear.