Optical and magnetic properties of Zn0.9Mn0.05Fe0.05O thin films deposited by RF-magnetron sputtering

Abstract

Zn_0.9Mn_0.05Fe_0.05O were synthesized by rf-magnetron sputtering in an argon gas environment show a hexagonal wurtzite structure without any secondary phases of dopants MnO or Fe₂O₃. The crystallite (D) parameters estimated from the XRD pattern disclose a significant decrease with argon partial gas pressure from 3.34 to 11.80 nm. The surface morphology of as-deposited films has a dense columnar microstructure with an average grain size of about 14–18 nm with roughness (RMS) from ∼2.86 to 7.67 nm. The sputtered thin films exhibit high optical transmittance in the visible range with a significant redshift as a function of working pressure. The energy band gap shows a slight increase with gas pressure in the range of about ∼3.05–3.36 eV. The films deposited for argon gas pressures of 12 & 15 mTorr have room-temperature ferromagnetism due to oxygen vacancies/defect concentrations in the host ZnO matrix.