Surface potential, fermi level and band gap energy of copper doped magnesium nickel ferrite nanoparticles

Optical, electrical, and electronic properties of materials are essential in the fabrication of electronic devices. These properties can be improved through doping and reduction of the size of a material to nanoscale. In this study, copper doped magnesium-nickel (CuxMg1-xNiFe2O4, for x=0.00, 0.15, 0.30, 0.45, 0.60, 0.75, 1.00) ferrite nanoparticles were synthesized using the citra-gel auto combustion method. The electronic and optical properties were evaluated using the scanning Kelvin probe microscopy (SKPM) and UV-visible, respectively. The UV-visible studies revealed that, the band gap energy was at the range of 3.600-3.750 eV. The band gap was noted to increase with copper content up to x=0.45 which then started to decrease. The undoped sample displayed the lowest band gap energy in comparison with the doped. SKPM analysis exhibited the surface potential in the range 4.361-5.002 eV for the area scan and 4.251-5.006 eV for the line scans for the samples. The sample with x=0.75 showed a positive work function for both area and line scans, and all the others had a negative work function. The doped ferrite exhibited the properties that could be applied in optical devices, storage devices, and recording devices.