Precise Estimation of Mobility of PFPE Lubricants Combining the Experimental Method and Numerical Method

The diffusion coefficient has been used to estimate the mobility of PFPE lubricant on hard disk media. In former researches, initial lubricant thickness distribution is assumed to be step function. And similar solution was used to estimate the diffusion coefficient. But based on our experimentally measured data, initial distribution is not step function but has inclined slope. It leads the over estimation of the diffusion coefficient especially for low mobility lubricants. In this paper, instead of assuming initial distribution is step function and using similar solution, the diffusion coefficient is estimated by the method combining the experimentally measured results and the numerical solutions. The estimated diffusion coefficient is much lower for the low mobility lubricants. Calculated thickness distribution agrees well with the experimentally measured distribution. The mobility and spreading characteristics of PFPE lubricants can be estimated precisely using this method.