We plan to perform transverse field and zero-field μSR experiments to investigate the temperature dependence of the relaxation rate in the superconducting phase of Rare-earth (RE=Sm and La) doped Phenanthrene (RExPhenanthrene). Through these measurements we expect to derive information on how the London penetration depth varies upon changing the chemical stoichiometry and the superconducting transition temperature, as well as information on the flux lines mobility. Zero-field experiments in SmPhenanthrene will provide information on the magnetic ground-state arising in this material and coexisting with the superconducting phase.