Effects of annealing temperature on the structure, electrical resistivity and infrared emissivity of PtOx films

PtOx films were deposited by direct current reactive magnetron sputtering in Ar/O2 mixture atmosphere. Subsequently, post-deposition heat treatments were conducted in air ambient at temperatures from 400 to 600 °C for 1 h with the heating rate of 10 °C/min. Effects of the annealing temperature on properties of PtOx films such as the structure, morphology, composition, electrical resistivity and infrared emissivity were studied. The as-deposited PtOx films mainly consisted of amorphous PtO and PtO2 compounds and decomposed to polycrystalline Pt slightly at 500 and 550 °C. As the annealing temperature increased, the films were decomposed completely at 600 °C. Due to the prompt release of oxygen at 600 °C, a great number of nano-scale pores were found on Pt films. The XPS analysis showed that the observed Pt 4f peaks would shift to lower binding energy with increasing the annealing temperature, which was consistent with the XRD analysis. The electrical resistivity and infrared emissivity of the films both increased when the annealing temperature was below 500 °C and decreased intensely at 550 and 600 °C.