Influence of morphology on thermal properties of Mn3O4 nanoparticles - A thermal lens study

Abstract

The shape dependent optical and thermal properties of Mn₃O₄ nanostructures synthesized via precipitation method is investigated in the present study. By varying the stirring temperature during the precipitation process, a series of nanoparticles with distinct morphologies were produced, transitioning from agglomerated structures to nanorods and further to nanocubes. Notably, the morphological evolution of Mn₃O₄ nanoparticles as influenced by stirring temperature has not been previously documented in the literature. The thermal diffusivity of Mn₃O₄ nanoparticles was quantified through a dual beam collinear thermal lens technique. An increase in stirring temperature resulted in the variation in thermal diffusivity values which substantiates the role of morphology in governing the thermo-optic characteristics of Mn₃O₄. The alterations are explained using absorption and emission spectra analysis. The thermal diffusivity values of Mn₃O₄ nanoparticles were found to be more than that of the base fluid, ethylene glycol (0.93 ×10⁻⁷ m²/s) varying between 5.71 ×10⁻⁷ m²/s to 24.93 ×10⁻⁷ m²/s. The exceptionally high thermal diffusivity values found in these samples suggest their potential for various technological applications, particularly in cooling systems. This study emphasizes the relationship between morphology and thermal properties, paving the way for the development of materials with tailored thermal behaviors for a wide range of applications.