Effect of ZrO2 addition on the structural, optical and electrical properties of MgO protective films

The effects of ZrO2 additions on the physical as well as electrical properties of the MgO thin films, deposited on slide glass substrates by electron beam evaporation, have been investigated. As the ZrO2 molar concentration ratio increased, the intensity ratio of the (200) peak relative to the (111) peak was observed to increase with a corresponding peak shift to lower diffraction angles as a result of the substitutional solid solution between Mg and Zr. The film density, which was calculated from the measured refractive index and the equivalent refractive index, had a maximum at a ZrO2 molar concentration ratio of 3 mol% and gradually decreased and saturated with increasing ZrO2 concentration ratio. At a ZrO2 molar concentration ratio of 3 mol%, the deposited MgO-ZrO2 layer exhibited lower discharge voltages compared to a conventional MgO layer, probably due to its increased density.