Experimental study of slider–lubricant interaction with different slider designs

In this study, a new type of femto slider (Panda IV) with improved force arrangement and higher air pressure/higher stiffness at trailing edge of the slider was evaluated and compared experimentally with our previous type of femto sliders (Panda II and III). The evaluations were conducted on the Candela 5100 Optical Surface Analyzer (OSA) with the VENA CSS/load–unload system attached. Disks coated with a layer of 1.2 nm lubricant were specially prepared with a lubricant step for the comparison tests. Flying height (FH) of each slider was calibrated by bump disk with 3.5 nm bump height for maintaining the consistent FH during the tests. The relative amount of lubricant redistribution was analyzed with an OSA immediately after each slider is flown on-track for a period of time. It is found that the amount of lubricant transferred or the slider–lubricant interaction are minimized by reducing the size of slider’s central trailing pad. Finally, possible explanations on the lubricant transfer are discussed.