  A new disordered atom configuration in Fe2CrGa alloy has been created by
ball-milling method. This leads to a significant enhancement of the magnetic
moment up to 3.2~3.9 {\mu}B and an increase of Curie temperature by about 200
K, compared with the arc-melt samples. Combination of first-principles
calculations and experimental results reveals that Fe2CrGa alloy should
crystallize in Hg2CuTi based structure with different atomic disorders for the
samples prepared by different methods. It is addressed that magnetic
interactions play a crucial role for the system to adopt such an atomic
configuration which disobeys the empirical rule.
