$T_{c}$ and Upper Critical Field Slopes of Nb/Cr Bilayers

We studied various superconducting properties of SC/AF bilayer films using Nb and Cr, observing the changes as the thicknesses of each metal was varied (Nb was held at 51 nm as Cr ranged from 5 to 100 nm, Cr was held at 50 nm as Nb was varied from 5 to 125 nm). These were grown by DC magnetron sputtering onto (100) oriented Si substrates. The samples were then attached to wires and cooled in a different vacuum chamber to $\approx$ 6 K, where we measured their critical temperatures ($T_c$) and perpendicular critical fields ($B_{c2}$) at low field strenghs ranging from 0 to $\approx$ 450 mT. We will compare our findings to the proximity effect theory for the $T_c$ and $B_{c2}$ of thin film bilayers.