  It is well known that the Casimir force between two half-spaces is dictated
by their electromagnetic properties. In particular, when one of the half-spaces
is mainly metallic or dielectric and the other is mainly magnetic, it is
possible to show that the force is repulsive. This has attracted lots of
interest towards the study of metamterials (MMs) in the context of Casimir
effect, as their magnetic activity might help bring the idea of Casimir
repulsion from the theoretical realm to experimental verification. In this
paper we investigate the possibility of repulsion when the MM magnetic
permeability is given not by a Drude-Lorentz behavior, but by a model put
forward by Pendry et al. . After introducing the model and deriving the
necessary formulas, we show that it is impossible to achieve repulsion with
such a model and present a qualitative discussion of why this is so.
