Structural and photoacoustic studies of Zn4Sb3 and ZnSb phases prepared by mechanical alloying

The structural and photoacoustic properties of nanostructured zinc antimonides Zn4Sb3 and ZnSb prepared by mechanical alloying were studied by x-ray diffraction (XRD) and photoacoustic absorption spectroscopy (PAS). The XRD patterns revealed the existence of Zn4Sb3 and elemental Zn for 10 h of milling, Zn4Sb3 and ZnSb for 20 h of milling, and ZnSb and elemental Zn for 30 h of milling. Using the Rietveld structural refinement procedure, the experimental XRD patterns were simulated and the relative amounts of each phase for each of the milling times above were calculated. The thermal diffusivity values corresponding to each milling time were measured from the PAS signal amplitude and phase. Using the thermal diffusivity value and the relative amounts of ZnSb and elemental Zn, we estimated the thermal diffusivity for the ZnSb phase in nanometric form. The result seems to corroborate the suggestion of other researchers that the thermal conductivity tends to be smaller in materials with nanometric crystallites.