フォースモジュレーション法によるPFPE(Perfluoropolyether)を塗布した磁気ディスクの動的変形特性

抄録

To reduce the probability of head-crash in higher density magnetic systems, new extremely thin protective layers against wear and corrosion must be applied on magnetic head-disk interfaces. In this study, dynamic deformation of properties lubricant and of lubricant and DLC (Diamond-like Carbon) film compound layer were evaluated by the force modulation method. With regard to hard disks coated with DLC film and PFPE (Perfluoropolyether), their surface dynamic deformation properties such as storage modulus, loss modulus and Tan δ, etc., have been evaluated by AFM (Atomic Force Microscope). Concretely, the characteristics of visco-elasticity related with the existence of lubricants on the valley and hill parts of the hard disk surface and these function after a micro-wear test were estimated with the force modulation method. The main results of above-mentioned tests are as follows.
[1] Viscosity properties like loss modulus and Tan δ of valleys are higher than those of hill. It is considered that the viscosity is corresponding to the existence quantity of lubricant.
[2] Micro-wear properties such as wear depth and wear volume of a PFPE coated disk are lower than those of the disk without PFPE.
[3] The wear of PFPE coated hard disks has shown that after micro-wear tests with a high load Tan δ in hill parts of surface is increased a little as evaluating its viscosity. On the other hand, Tan δ in the valley parts decreased under a high load in micro-wear test. It is thought that lubricants have been removed by the micro-wear test.