Characteristics of dual lubricant layers

Lubricant characteristics of dual lubricant layers, which consist of a first-lubricant bonded layer and second-lubricant mobile layer, were studied. The interface durability is evaluated by a pin-on-disk test. The spin-migration characteristic is evaluated based on the change in thickness of layers after disk spinning. The mobility is estimated from spreading profiles from the lubricant step. Dual lubricant layers , which consists of Z-dol as a mobile layer and Z-tetraol or AM as a bonded layer, shows high mobility, high interface durability, and low spin-migration performance. It is considered that these characteristics can be attributed to higher interaction between the bonded lubricant and the mobile lubricant due to strong polar end groups of the bonded lubricant.