T. Ivetić

Investigation of Zinc-Stannate Synthesis Using Photoacoustic Spectroscopy

Mixtures of ZnO and SnO2 powders, with molar ratio of 2:1, were mechanically activated for 40, 80 and 160 minutes in a planetary ball mill. The resulting powders were compacted into pellets and non-isothermally sintered up to 1200˚C with a heating rate of 5˚C/min. X-ray diffraction analysis of obtained powders and sintered samples was performed in order to investigate changes of the phase composition. The microstructure of sintered samples was examined by scanning electron microscopy. The photoacoustic phase and amplitude spectra of sintered samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled determination of photoacoustic properties including thermal diffusivity. Based on the results obtained a correlation between thermal diffusivity and experimental conditions as well the samples microstructure characteristics was discussed.

Combined FTIR and SEM-EDS study of Bi2O3 doped ZnO-SnO2 ceramics

The effects of Bi2O3 addition on the phase composition, microstructure and optical properties of ZnO–SnO2 ceramics were investigated. Starting powders of ZnO and SnO2 were mixed in the molar ratio 2:1. After adding Bi2O3 (1.0 mol.%) this mixture was mechanically activated for 10 min in a planetary ball mill, uniaxially pressed and sintered at 1300°C for 2 h. Far‐infrared reflection spectra were measured (100–1000 cm–1). To investigate the occurred differences in FTIR spectra, the Bi2O3‐doped sample was examined more carefully with a Perkin–Elmer FTIR spectrometer (Perkin Elmer, Waltham, MA, USA) connected with a Perkin–Elmer FTIR microscope and itemized points of interest were also studied with SEM‐EDS.

Photoacoustic and Optical Properties of Zinc-Stannate Thin Films

Thin films of single-phase zinc-stannate (Zn2SnO4) were grown by rf magnetron sputtering onto glass substrates. Transmission in the visible range was measured allowing determination of the energy gap and thickness of analyzed thin film samples using interference fringes. The photoacoustic phase and amplitude spectra of all samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled calculation of thermal diffusivity, the coefficient of minority carrier diffusion, their mobility and lifetime.