MACRO AND MICROTRIBOLOGICAL STUDIES OF CRO2 VIDEO TAPES

Atomic force microscopy (AFM) and its modification-friction force micr oscopy (FFM) are becoming increasingly important in the understanding of friction, wear, lubrication and nanomechanical property measurement s. We describe modified AFM and FFM techniques and present data on mic rotribological studies of two CrO2 video tapes. Macro-scale friction m easurements were also made on the two tapes. We have observed that mac ro-scale friction is higher than that on micro-scale. Lower values of micro-scale friction as compared to macro-scale friction may be becaus e of less ploughing contribution in micro-scale friction measurements. The directionality effects observed in micro-scale friction may come from the asymmetrical transfer of wipe material or from the calenderin g. Differences in the macro-scale friction in the two tapes appear to correlate with the changes in scratch resistance, wear resistance and the hardness of the tape surface on a micro-scale to nano-scales. It i s demonstrated that AFM/FFM techniques are valuable in the fundamental understanding of tribology of magnetic tapes.