Synthesis, structure and optical properties of Indium filled CoSb3 nanomaterials

Abstract

Abstract The nano-sized InyCoSb3 skutterudites (y = 0.0125, 0.025, 0.0375 and 0.0625) were synthesized by solvo-/hydrothermal method at 240 °C for 24 hours. The surface morphology of as-synthesized samples analyzed by Field Emission Scanning Electron Microscope (FESEM) shows nanoparticles with size of around 50 nm depicting narrow size distribution and Electron X-ray diffraction spectroscopy (EDX) spectrum confirms the purity of the In-filled CoSb3 nanomaterials. The powder X-ray diffraction (pXRD) pattern reveals all the compositions showing diffraction peaks indexed to cubic phase of CoSb3 with Space group Im 3 ¯ . However, no significant variation in the pXRD pattern of In filled CoSb3 as compared to pure CoSb3 justifies the successful filling of voids in cage-like structure of CoSb3 with Indium. FTIR spectra of In filled CoSb3 presents vibration modes below 1000 cm−1 corresponding to Co-Sb bonding and Cobalt complex. A significance of In filling into CoSb3 structure is also evident. A wide absorption has been witnessed from UV region to large part of visible region, hence indicating the effect of nanoparticle, agglomeration and filling.