Structural, electronic, magnetic, and optical properties of Fe-doped Na2ZnP2O7 host: ab-initio calculation

Recent experiments on the optical characterization of transition metal ions doped Na2ZnP2O7 host lattice, show promise as luminescent materials. A detailed study using ab-initio DFT-based calculations to understand how the properties of the Na2ZnP2O7 host lattice are affected by the Fe dopants is carried out. The GGA and GGA + U functionals were used to determine the electronic and optical properties of the host lattice and Fe ion doped Na2ZnP2O7.. Full structural geometric optimization was performed for pristine Na2ZnP2O7 host lattice, super-cell and Fe doped super-cell. The computed electronic band structure, density of states, and dielectric functions for the pristine and doped crystal structure reveal changes due to the Fe dopant ion, which induces various states within the band gap of Na2ZnP2O7 lattice. The total magnetic moment of the host lattice is found to be zero, which implies nonmagnetic behavior as shown by the spin-polarized band structure, while the spin-polarized band structure of the Fe-doped Na2ZnP2O7 structure shows a ferromagnetic character. This study provides new clues about the diphosphate compounds with transition metal dopant ions.