Lateral force versus load measurements

The friction coefficients of [Bmim] PFe] on M-Ti02 and D-Ti02 films as a function of lateral force for Si tip at various normal loads are also measured and are shown in Fig. 15. It showed in Fig. 15 that the fiiction coefficients of [Bmim][PF6] on both M-Ti02 and D-Ti02 films determined from the slopes of lateral force versus normal load plots were in the same scale (0.0025 for M-Ti02 films and 0.0026 for D-Ti02 films). The observation showed that tip can sHp easily with the existence of Pmim] [PF ] on... 

While the tip is oscillating in the transverse or lateral direction, the cantilever is brought into contact by extending the Z-piezoceramic transducer at constant speed by a known distance and is then retracted to its initial position. The friction force is proportional to the amplitude of the tip s lateral displacement analyzed by the lock-in technique. Measuring the lateral component while varying the load achieves in one step the measurement of the friction versus load. 

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