Dispersion forces between metal and dielectric plates separated by a magnetic fluid

The formalism of the Lifshitz theory has been used for determining the pressure exerted by dispersion forces between metal and dielectric plates separated by a thin layer of a magnetic fluid. Numerical calculations are performed for gold and quartz glass plates and the magnetic fluid consisting of kerosene and magnetite nanoparticles at room temperature. For this purpose, we have used familiar representations of dielectric properties of gold and quartz glass along the imaginary frequency axis; corresponding representations have also been obtained for magnetite and kerosene. The dispersion pressure has been analyzed as a function of the distance between the plates, the volume fraction of magnetite particles in the magnetic fluid, and their diameter. At large separations between the plates, simple analytic expressions for this pressure have been derived. Possible application of results has been considered.