  Measurements of the in-plane magnetic field penetration depth \lambda_{ab} in
Fe-based superconductors with the nominal composition SmFeAsO_0.85
(T_c\simeq52K) and NdFeAsO_0.85 (T_c\simeq51K) were carried out by means of
muon-spin-rotation. The absolute values of \lambda_{ab} at T=0 were found to be
189(5)nm and 195(5)nm for Sm and Nd substituted samples, respectively. The
analysis of the magnetic penetration depth data within the Uemura
classification scheme, which considers the correlation between the
superconducting transition temperature T_c and the effective Fermi temperature
T_F, reveal that both families of Fe-based superconductors (with and without
fluorine) falls to the same class of unconventional superconductors.
