Study of temperature dependent volume expansion in Nanomaterials
A temperature dependent model is formulated to study the thermo-elastic properties of nanomaterials. The model is based on quasi-harmonic approximation and also Anderson Gruneisen parameter is considered to vary linearly with temperature. Present model is modified form of equation (EOS) developed recently by Goyal and Gupta to explain the thermal behavior of solids. The calculated values for thermal expansion coefficient under varying temperature conditions are compared with the available experimental data for fullerene (C60), 20-nm nickel, and 15nm (Ni+Fe) nanocrystal. It is found that the results obtained by the present model approach are comparable to the experimental results reported earlier which verifies the suitability of the model. The same model is further extended to study the variation in volume and bulk modulus with temperature in nanomaterials. The results show the same trend of expansion as observed in solids under varying temperature.
Keywords: Anderson Gruneisen parameter; volume expansion; thermal expansion coefficient; equation of state; Bulk modulus