The electronic, magnetic and optical properties of double perovskite A2FeReO6 (A=Sr, Ba) from first principles approach

[Display omitted] A density functional theory (DFT) employing generalized gradient approximation (GGA) and modified Becke Johnson (TB-mBJ) potential have been used to study the electronic, magnetic and optical properties of A2FeReO6 (AFRO). The presence of indirect band gap of majority electrons at EF and the conducting behaviour of minority electrons predicts these materials to be a half metallic ferrimagnets. The GGA band gaps are enhanced with the implementation of a new electron exchange semilocal potential called TB-mBJ. The real and imaginary parts of dielectric function, refractive index, absorption coefficient and reflectivity are calculated. The inter-band transitions to the optical properties are analyzed with the band structures.