van der Waals force calculation between laminated media, pertinent to the magnetic storage head-disk interface

Lifshitz theory of van der Waals interactions is applied to the geometry and materials of the head-disk interface (HDI). A simplified two-substrate model with intervening air gap is used to illustrate the effects of retardation. The calculation of the Hamaker functions for increasingly complex layered structures is then presented to illustrate the importance of the multilayered nature of the HDI on the van der Waals (vdW) interaction. The full Lifshitz-multilayer calculation is then compared to approximations of the vdW force and relative errors are displayed. The results indicate the necessity of performing the full Lifshitz calculation on a realistic layered model of the HDI for accurate force modeling.