Superlubricity Relevant in Hard Disk Drive Applications

Reduction of head-media spacing (HMS) keeps crucial during the increase of areal density of hard disk drives (HDD). The design of hard disk drive with a superlubric interface is reported with two schemes for HDI design to realize superlubricity. For the first scheme, the DLC layer is kept on the disk while removing the lubricant layer. The DLC layer on the transducer is replaced by graphene-like layer. The direct contact between head and disk could reduce the HMS to about 2.3 nm. For the second scheme, the DLC layer on disk is further replaced by graphene and the HMS could be reduced to below 1 nm. For the first scheme, the basic proof of concept experiments are conducted using micro-scale graphite island samples. Ultralow COF, with the average of 0.0344 on the interface of single crystalline graphite surface and DLC substrate is demonstrated by AFM. What’s more, the temperature dependence of friction between single crystalline graphite and DLC is measured by micro-force sensor mounted on micro-manipulator. The results show that heating helps to significantly decrease the friction. Desorption of contaminants along the interface is speculated to be the key mechanism for temperature dependence of friction. This work provides the concept of large-scale superlubricity relevant in HDD applications, which could be a promising technology to ultimately reduce HMS for future HDI development.