Far infrared properties of bulk sintered and thin film Zn2SnO4

Room temperature far infrared reflectivity spectra of single phase spinel zinc-stannate thin films, prepared by rf magnetron sputtering on a glass substrate, and bulk sintered samples were measured. The sintered samples were obtained by mechanical activation of starting ZnO and SnO2 powders for 10 min followed by sintering at 1300 °C for 2 h. The reflectivity diagrams obtained for bulk samples were numerically analyzed using the four-parameter model of coupled oscillators. The optical parameters were determined for six observed ionic oscillators belonging to the spinel structure and two additional oscillators originating from the sintering procedure resulting from pores and grain boundaries. The reflectivity diagrams obtained for thin film samples were analyzed using the four-parameter model for optical phonons with a standard optical multi-layer technique.