Structural, opto-electronics and magnetic study of Fe/Si doped ZnO

Abstract

Structural, opto-electronics and magnetic hysteresis properties have been studied of sol-gel synthesized Zn(0.96875)Si(0.03125)-xFexO (0x0.03125) nano-particles. The crystallites belong to a wurtzite P6(3)mc space group. The ratio of Si:Fe is varied in these materials. Si4+ and Fe3+ both attract oxygen to the lattice. The excess oxygen content reduces oxygen vacancies and further creates oxygen interstitials. However, there is a limit of oxygen intake as space is used up when a larger Fe3+ ion substitutes a smaller Si4+ ion. Hence, with increasing Fe3+ content the amount of oxygen added to the lattice starts reducing firstly, due to the lesser charge and secondly due to the larger size of Fe3+. This trend results in optimized maxima of oxygen content and affects the lattice parameters, lattice strain, defect states thereby tuning bandgap and photoluminescent properties. Excluding the pure ZnO sample, all samples exhibit weak ferromagnetic interactions that enhance with increasing Fe content.