Theoretical Calculation of the Low-Density Transport Properties of Monatomic Silver Vapor

Abstract

Calculations of low-density transport property collision integrals are used to obtain the high-temperature transport properties of silver atoms as a function of temperature. The collision integrals depend on the two-body interaction potentials between silver atoms in various electronic states. Contributions are included from the ground X 1 + g and excited 3 + u molecular electronic states of the silver dimer that dissociate to two ground-state silver atoms and from the excited A 1 + u molecular state that dissociates to a ground state and an excited state silver atom. Spectroscopic constants are available for these three electronic states, and these spectroscopic constants have been used to determine the Hulburt-Hirschfelder (HH) potentials for these three states. The HH potential is perhaps the best general-purpose potential for representing atom-atom interactions. This potential depends only on the spectroscopic constants, and can be used to calculate the viscosity and diffusion collision integrals for the three molecular electronic states. The collision integrals are then degeneracy averaged over the three states. The heat capacity of silver atoms is also calculated at high temperatures. These results provide the information required to obtain the thermal conductivity, viscosity, and self-diffusion coefficients of silver atoms over a wide temperature range from the boiling point of silver to temperatures at which ionization becomes important.

Determination of volume, scaling exponents, and particle alignment of nanoparticle agglomerates using tandem differential mobility analyzers

“…In our experimental setup, the residence times along the 40 cm center region (where the gas temperature is almost equal to furnace set temperature) are estimated to be 0.72 and 0.65 s for 800 and 900 1C, respectively. At 900 1C the diffusion coefficients of silver vapor and of nitrogen vapor were estimated to be 3.09 Â 10 À 5 and 2.38 Â 10 À 4 m 2 /s using Biolsi and Holland's (2007) and Cubley and Mason's (1975) results, respectively. The binary diffusion coefficient of silver vapor in nitrogen gas at 900 1C was estimated to be 4.97 Â 10 À 5 m 2 /s using simple kinetic theory.…”

Properties of silver nanoclusters and bulk silver, using a new and accurate HFD-like potential, including many-body interactions: the inversion scheme and molecular dynamics simulation

“…The direct inversion procedure for the determination of pairpotential using reduced viscosity collision integrals is described in detail in the previous papers. 9,10 The reduced pairpotential energy function of silver was obtained using the inversion of the reduced viscosity collision integrals of silver vapor 5 and is presented in Fig. 1.…”

“…1, our calculated pair-potential is in good agreement with the average Ag-Ag interaction potential calculated by Biolsi and Holland. 5 They computed the Ag-Ag interaction energies for three lowlying electronic states of Ag 2 using the Hulburt-Hirschfelder…”

“…1,2 Small clusters of silver atoms are of special interest because they can serve as prototypes for solid surfaces, which have important catalytic properties in bulk and also as nanosilver surfaces. [3][4][5] They are also important in the formation of photographic images. 6 Therefore, understanding and predicting the properties of silver nanoclusters are desired for theoretical and practical applications.…”

“…7 Recently, some theoretical work was carried out to calculate the different properties of silver and silver alloy nanoclusters (such as the melting process) using the MAEAM, EAM, and QSC interaction potentials. 2,5,[15][16][17] In order to test our new model for the nanocluster systems, we used the new interaction potential to compute the equation of state and some of the properties of the silver nanoclusters.…”