Structural, Thermal, Optical, and Photoacoustic Study of Mechanically Alloyed Nanocrystalline SnTe

• Autor(a) principal: Borges,Zeane Vieira
• Data de Publicação: 2018
• Outros Autores: Poffo,Claudio Michel, Lima,João Cardoso de, Souza,Sérgio Michielon de, Trichês,Daniela Menegon, Biasi,Ronaldo Sérgio de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Materials research (São Carlos. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392018000400228
• topic: Semiconductors; Nanocrystals; Mechanical alloying; Thermoelectric materials; X-ray diffraction; Photoacoustic absorption spectroscopy

A nanostructured SnTe phase was produced by mechanical alloying after 2 h of milling. Part of the as-milled powder was annealed and its X-ray diffraction (XRD) pattern was recorded. The XRD patterns of the as-milled and annealed samples were refined using the Rietveld method. After annealing, partial decomposition of the SnTe phase was observed and corroborated by estimating the mean crystallite size using a Willianson-Hall plot. The Cowley-Warren parameter α SnTe CWfor the first coordination shell was calculated, showing a preference for homopolar pairs. This preference is consistent with the partial decomposition observed. According to the optical absorbance spectra, the band gap energy is inversely proportional to crystallite size, following a decaying exponential function. From the photoacoustic absorption spectroscopy measurements, the thermal diffusivity parameter and the transport properties of as-milled and annealed SnTe powder were determined.