Abstract
The thickness dependency of damping coefficients and spring constants of liquid bridges of PFPE lubricant were measured by means of regression analysis of damping vibration of the liquid bridge which were formed between a diamond tip and the surface of a magnetic disk. Two type of PFPE lubricants having different molecular weight (Zdol2000 and Zdol4000) with the thicknesses of roughly 8nm, 20nm, and 40nm, were coated on the DLC surface. The damping values expressed and the spring constants had U-shaped profile along with the bridge elongation as reported in the previous study. In the thinner film (8nm), it was confirmed that the both values had no increase after the minimum value (L-shaped profile), and the damping value and the absolute of spring constant were a few times as large as those of the thicker films.
