Structural, optical and thermal characterization of nanostructured CdSe obtained by mechanical alloying

• Mechanical alloying of Cd and Se promoted the nucleation of CdSe with few hours of milling.
• A CdSe polymorphism was quantified by XRD using the Rietveld Method.
• 20 h of milling promoted the nucleation of a metastable Se phase.

A CdSe nanostructured alloy was produced by high energy Mechanical Alloying (MA). The existence of three crystalline phases, two CdSe polymorphs and a small fraction of CdO phase, was revealed through X-ray powder diffraction. With continued MA process, the CdO phase was dispersed between the nanostructures of zinc blende (ZB) and wurtzite (WZ). Differential Scanning Calorimetry (DSC) measurements indicated sublimation at 122 °C confirmed by thermal treatment. Raman spectroscopy revealed that the sublimated material was composed by a trigonal Se. After the thermal treatment, a partial phase transition from ZB to WZ was observed, which is in agreement with that observed by DSC, as well as by nucleation of the CdSeO3.