  In this article, we consider spherical thin shells of matter surrounding
black holes in F(R) theories of gravity. We study the stability of the static
configurations under perturbations that conserve the symmetry. In particular,
we analyze the case of charged shells outside the horizon of non--charged black
holes. We obtain that stable static thin shells are possible if the values of
the parameters of the model are properly selected.

General Relativity and Quantum Cosmology