  Here we investigate the temperature dependence of anomalous Hall effect in
Hf/GdFeCo/MgO sheet film and Hall bar device. The magnetic compensation
temperature ($T_{comp}$) for the sheet film and device is found to be ~240 K
and ~118 K, respectively. In sheet film, spin-flopping is witnessed at a
considerably lower field, 0.7 T, close to $T_{comp}$. Unlike sheet film, triple
hysteresis loops have been observed in the Hall bar device, just above
$T_{comp}$. Moreover, the temperature-dependent anomalous Hall resistance
($R_\mathrm{AHE}$) responds unusually when a perpendicular magnetic field is
applied while recording the $R_\mathrm{AHE}$. The zero-field $R_\mathrm{AHE}$
scan suggests the Hall signal generates solely from the FeCo moment. However,
the 3 T $R_\mathrm{AHE}$ scan, which seems to be following the net
magnetization response of the device, is explained by considering the low field
spin-flopping around the compensation temperature. The results presented here
give important insight to understand the complex AHE behavior of ferrimagnets
for their spintronic applications.
