  We present a comprehensive study of broadband spin pumping utilizing the
inverse spin Hall effect phenomena in bilayer samples comprising Ni81Fe19 (15
nm) and NbN (with NbN thickness varying from 20 nm to 140 nm), conducted over a
temperature and frequency range spanning from 300 K to 4 K and 2 GHz to 12 GHz,
respectively. Our investigations reveal a systematic shift in ferromagnetic
resonance fields, amplitude, and line widths as functions of both frequency and
temperature. Notably, we observed a temperature-dependent increase in the spin
Hall angle value, surpassing previously reported values. Furthermore, our
results demonstrate a pronounced temperature dependence in the inverse spin
Hall effect voltage, exhibiting a significant reduction below the Tc. This
reduction in inverse spin Hall effect voltage is accompanied by an increase in
the linewidth of the ferromagnetic resonance mode.
