  We report perpendicular magnetic anisotropy in the ferromagnetic Heusler
alloy Co$_2$MnGa in a MgO/Co$_2$MnGa/Pd trilayer stack for Co$_2$MnGa
thicknesses up to 3.5 nm. There is a thickness- and temperature-dependent spin
reorientation transition from perpendicular to in-plane magnetic anisotropy
which we study through the anomalous Hall effect. From the temperature
dependence of the anomalous Hall effect, we observe the expected scaling of
$\rho_{xy}^{AHE}$ with $\rho_{xx}$, suggesting the intrinsic and side-jump
mechanisms are largely responsible for the anomalous Hall effect in this
material.
