  A model binary hybrid system composed of a randomly distributed rare-earth
ferromagnetic (Gd) part embedded in an s-wave superconducting (Nb) matrix is
being manufactured to study the interplay between competing superconducting and
ferromagnetic order parameters. The normal metallic to superconducting phase
transition appears to be very sensitive to the magnetic counterpart and the
modulation of the superconducing properties follow closely to the
Abrikosov-Gorkov (AG) theory of magnetic impurity induced pair breaking
mechanism. A critical concentration of Gd is obtained for the studied NbGd
based composite films (CFs) above which superconductivity disappears. Besides,
a magnetic ordering resembling the paramagnetic Meissner effect (PME) appears
in DC magnetization measurements at temperatures close to the superconducting
transition temperature. The positive magnetization related to the PME emerges
upon doping Nb with Gd. The temperature dependent resistance measurements
evolve in a similar fashion with the concentration of Gd as that with an
external magnetic field and in both the cases, the transition curves accompany
several intermediate features indicating the traces of magnetism originated
either from Gd or from the external field. Finally, the signatures of magnetism
appear evidently in the magnetization and transport measurements for the CFs
with very low (less than 1 at. %) doping of Gd.
