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Synthesis and structural characterization of nanostructured SnSe2 obtained by Mechanical Alloying 
Zeane Vieira Borges1, Claudio Michel Poffo2 e Thiago Pulcinelli Orlandi Nogueira3
Departamento de Tecnologia, Universidade Federal do Amazonas, 69077-000 Manaus, Amazonas, Brasil.
Departamento de Física, Universidade Federal de Santa Catarina, Campus Trindade, C.P. 476, 88040-900 Florianópolis, Santa Catarina, Brasil.
Departamento de Física, Universidade Federal do Amazonas, 69077-000 Manaus, Amazonas, Brasil.
E-mail: zeaneufpa@gmail.com
Abstract
High-purity powders of Sn and Se elements were mixed with nominal composition Sn34Se66 and submitted to Mechanical Alloying technique (MA) [1] for 5 min, 15 min, 45 min, 1h45 min, and 4 hours. Structural changes were studied by X-rays Diffraction (XRD) and Rietveld method (RM) [2]. After 5 mins, we observed the nucleation of SnSe2 hexagonal phase. Therefore Sn and SnO2 phases were observed up as minority to 15 mins and 4 hours, respectively. Rietveld quantification shows the decreasing level of SnSe2 phase while an increase of SnO2 phase after 1h45mins of milling. Williamson-Hall equation [3] was used to calculate crystallite size and strains. Between 5 and 15 mins, we see a significant decrease of crystallite size of 31 nm to 14 nm, while a strain growth were observed. After 45 min, the crystallite size shows smooth decrease, indicating a balance growth between the interfacial component and SnSe2 phase. Strain stabilizes at 1h 45 mins of milling. Based on the previous results, SnSe2 was again produced by 1h30min of milling to perform measurements of XRD, Photoacoustic Absorption Spectroscopy (PAS) and Differential Scanning Calorimetry (DSC) measurements in order to characterize its structural, optical and thermal properties.
Key words: Mechanics Alloying, X-rays Diffraction and Rietveld method. 
References: 
[1] C. Suryanarayana. Progress in Materials Science. 46 (2001) 1-184.
[2] H. Rietveld. J. Appl. Crystallogr. 2 (1969) 65-71.
[3] G. Williamson et al. Acta Metall. Mater. 1 (1953) 22-31.