  Spin gapless semiconductors exhibit a finite band gap for one spin channel
and closed gap for other spin channel, emerged as a new state of magnetic
materials with a great potential for spintronic applications. The first
experimental evidence for the spin gapless semiconducting behavior was observed
in an inverse Heusler compound Mn2CoAl. Here, we report a detailed
investigation of the crystal structure and anomalous Hall effect in the Mn2CoAl
using experimental and theoretical studies. The analysis of the high-resolution
synchrotron x-ray diffraction data shows anti-site disorder between Mn and Al
atoms within the inverse Heusler structure. The temperature-dependent
resistivity shows semiconducting behavior and follows Mooijs criteria for
disordered metal. Scaling behavior of the anomalous Hall resistivity suggests
that the anomalous Hall effect in the Mn2CoAl is primarily governed by
intrinsic mechanism due to the Berry curvature in momentum space. The
experimental intrinsic anomalous Hall conductivity (AHC) is found to be 35
S/cm, which is considerably larger than the theoretically predicted value for
ordered Mn2CoAl. Our first-principle calculations conclude that the anti-site
disorder between Mn and Al atoms enhances the Berry curvature and hence the
value of intrinsic AHC, which is in a very well agreement with the experiment.
