A molecular dynamics study on iridium

Abstract

Abstract:In this study, molecular dynamics simulations are performed by using a modified form of Morse potential function in the framework of the Embedded Atom Method (EAM). Temperature-and pressure-dependent behaviours of bulk modulus, second-order elastic constants (SOEC), and the linear-thermal expansion coefficient is calculated and compared with the available experimental data. The melting temperature is estimated from 3 different plots. The obtained results are in agreement with the available experimental findings for iridium.

Thermophysical properties of iridium at finite temperature

“…Our results are almost identical with the experimental results in Ref. [40] up to 1500 K with maximum deviation of 18.71% at 1800 K, and our results are also in excellent agreement with the theoretical results obtained by Ferah et al [5] Temperature/K 0 20 40 60 300 800 1300 1800 2300 Relative enthalpy/kJSmol -1 this study expt. [40] Ref.…”

“…To the best of our knowledge, for the first time, in this paper, we have carried out the study of thermal expansion of Ir up to melting temperature because, at higher temperatures, the experimental results of β P change appreciably and the theoretical studies are limited up to 900 K. By conducting a detailed comparison of our results with experimental results, we find that our results are almost identical to experimental results obtained by Touloukian et al (recommended values) up to 1500 K. [34] The maximum deviation of our computed results with the results obtained by Touloukian et al is 6.9% at 2500 K. The results obtained by Arblaster [35] are also in good agreement with 2.78% variation at 2500 K. The results obtained by Caldwell [36] are in excellent agreement with our computed results up to 1300 K. The results obtained by Halvorson [37] are in excellent agreement with our theoretical results at low temperature and high temperature with maximum deviation of 1.05% at 1800 K. Our computed results are also better than the theoretical results obtained by Ferah et al [5] and Katsnelson et al [38] Ferah et al [5] used molecular dynamics simulations by using modified Morse potential and employed embedded atom method (EAM) to study temperature variation of thermal expansion. Katsnelson et al [38] used pseudopotential obtained by Ivanov et al (I) and modified form of the pseudopotential of Ivanov et al (MI) to study the temperature variation of thermal expansion.…”

“…In order to compare our computed results of volume thermal expansion with the experimental and other theoretical results, we have converted the results in the form of relative volume thermal expansion. The temperature variation of relative volume thermal expansion along with the experimental findings [34][35][36][37] and other theoretical results [5,38] is shown in Fig. 3.…”

“…Temperature dependence of computed values of relative or scaled enthalpy (E H (T )−E H (300 K)) up to melting temperature and the experimental results up to 1800 K obtained by Robie et al [40] and the theoretical results up to 900 K obtained by Ferah et al [5] are compared in Fig. 5.…”

“…Very recently, many attempts have successfully been made to theoretically investigate the static, lattice dynamical and thermodynamic properties of Ir using first principle methods [3,4] and other methods [5,6] including pseudopotential. [1,2,[7][8][9] All these studies were carried out to theoretically understand the behavior of microscopic properties of materials.…”