Weathering induced morphological modification on the thermal diffusivity of natural pyrrhotite

ǂa ǂthermal lens study

Mohanachandran Nair Sindhu Swapna (Author), V. Gokul (Author), Vimal Raj (Author), R. Manu Raj (Author), S. N. Kumar (Author), Sankaranarayana Iyer Sankararaman (Author)

Abstract

Natural pyrrhotites have gained significant attention due to their interesting electronic, antimicrobial, and chemical properties. The present work attempts to explore the morphology-induced modifications in the thermal characteristics of natural pyrrhotite due to ageing. The morphological, elemental, structure, optical, and thermal characterisations help in understanding the effect of ageing. The effects of five years of ageing of the sample are (i) Field Emission Scanning Electron Microscopic analysis reveals a morphological transformation from flakes to agglomerated powder, (ii) elemental analyses suggest the ageing induced compositional modification (iii) the Tauc plot analysis shows a bandgap energy modification from 1.46 eV to 1.92 eV, (iv) X-ray Diffraction (XRD), Fourier Transform Infrared, and X-ray photoelectron spectroscopic studies affirm the formation of oxy-hydroxides (v) the XRD data indicates an increase of dislocation density, and (vi) Photoluminescence study shows a deep violet emission evidenced through the CIE plot. The study by the thermal lens technique shows a lowering of thermal diffusivity study by 23%, due to the morphological modifications, adsorbed/chemisorbed hydroxyl groups, and the formation of secondary compounds due to oxidation and weathering. The phonon boundary scattering, weathering induced smaller grain size, reduced phonon mean free path, and point defects also account for the lowering of the thermal diffusivity value and thereby influencing its properties.

Keywords

pyrrhotite;thermal diffusivity;thermal lens;ageing;morphology;

Data

Language:	English
Year of publishing:	2021
Typology:	1.01 - Original Scientific Article
Organization:	UNG - University of Nova Gorica
UDC:	54
COBISS:	113318915
ISSN:	1478-6443
Views:	502
Downloads:	3
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