Negative entropy of mixing for vanadium-platinum solutions.
Journal Article (Journal Article)
The phonon densities of states for pure vanadium and the solid solutions V-6.25% Ni, Pd, Pt were determined from inelastic neutron scattering measurements. The solute atoms caused a large stiffening of the phonons, resulting in large, negative vibrational entropies of mixing. For V-6.25%Pt, the negative vibrational entropy of mixing exceeds the conventional positive chemical entropy of mixing. This negative total entropy of mixing should extend to lower concentrations of Pt, and the effect on the bcc solvus line is discussed. The experimental data were inverted to obtain interatomic force constants by using a Born-von Kármán model with an iterative optimization algorithm. The stiffening of bonds responsible for the decrease of entropy was found to occur mainly in first-nearest-neighbor solute-host bonds, and correlates in part with the solute metallic radius.
Full Text
Duke Authors
Cited Authors
- Delaire, O; Swan-Wood, T; Fultz, B
Published Date
- October 29, 2004
Published In
Volume / Issue
- 93 / 18
Start / End Page
- 185704 -
PubMed ID
- 15525182
Electronic International Standard Serial Number (EISSN)
- 1079-7114
International Standard Serial Number (ISSN)
- 0031-9007
Digital Object Identifier (DOI)
- 10.1103/physrevlett.93.185704
Language
- eng