Thermodynamic Properties Of Zinc Oxide [001] Nanowires Via First Principles Calculations  

¹Department of Physics, M. K. Bhavnagar University, Bhavnagar 364002, India

²Department of Physics, St. Xavier’s College, Navrangpura, Ahmedabad 380009, India

³Department of Physics, Faculty of Science, M. S. University of Baroda, Vadodara 390002, India

Adv. Mater. Lett., 2016, 7 (3), pp 246-252

DOI: 10.5185/amlett.2016.6147

Publication Date (Web): Feb 01, 2016

Copyright © IAAM-VBRI Press

Abstract

The size dependent vibrational and thermodynamical properties of Zinc Oxide Nanowire (ZnO NWs) along with its bulk counterparts has been studied using the first principles calculations within density functional theory. The thermodynamical parameters such as specific heat at constant volume, entropy, internal energy and Helmholtz energy as function of temperature for the different size of nanowires are obtained and compared with the bulk ZnO in wurtzite phase. We address the effects of structural confinement on the phonon dispersion, vibrational density of states and qualitatively on the sound velocities and thermal conductance. The phonon dispersion curves for considered ZnO nanowires and its bulk counterpart indicates dynamical stability. The band gap increases from bulk to nanowire and an inverse size dependency in the case of nanowires arising due to quantum confinement. The analysis of bands character in context of growth characteristics and thermodynamical properties are also discussed. Our findings will give some reference to the insight understanding of the electronic, vibrational and thermodynamical properties of size orientation dependent ZnO nanowire. 

Keywords

Zinc oxide nanowires, phonon, density functional theory, specific heat, Debye temperature.