Photoacoustic characterization of natural mineral pyrite (FeS2)

A single p-type crystal of the mineral, pyrite (FeS2) was characterized photoacoustically using the transmission detection configuration. Photoacoustic (PA) amplitude and phase spectra were measured using a specially constructed PA cell. The PA signals of different sample thicknesses were measured using an experimental setup with a semiconductor red laser (80 mW) as the optical source. The obtained amplitude and phase spectra for different thicknesses were numerically analyzed enabling determination of thermal diffusivity, mobility of minority free carriers and other parameters characteristic for this material.