  SrCoO2.5 (SCO) is a charge transfer insulator with 3d6 ground state
configuration leading to antiferromagnetic nature. It is observed that
substrate induced strain engineering modifies the ground state of SCO thin film
with 3d7L (L:O-2p hole) configuration causing negative charge transfer
energy.The consequent strong hybridization between O-2p and Co-3d bands causes
a hole in O-2p band leading to hole mediated unconventional ferromagnetic
ordering in SrCoO2.5 thin film. This opens up a new avenue to tune the
electronic structure vis a vis magnetic property via strain engineering.
