Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7722478 | International Journal of Hydrogen Energy | 2013 | 7 Pages |
Abstract
Thermodynamic parameters such as enthalpy and entropy of the vanadium-hydrogen solid solution are investigated as a function of aluminum content using hydrogen solubility data and the Sievert's constant. The enthalpy decreases with increase in the aluminum content. Entropy shows anomalous behavior as it first increases with the aluminum content for V1âxAlx (x: 0, 0.18, 0.37) but then substantially decreases for V0.48Al0.52. The lattice parameters and the electrical resistivity of the alloys are calculated to explain the mechanical and electronic effects on the thermodynamic parameters. It is found that the electrical resistivity of vanadium systematically decreases and the lattice constant increases with increase in aluminum content. The hardness of the alloys increases with aluminum which indicates that aluminum hardens the vanadium by simple solid solution effect. The variation of enthalpy and entropy is explained on the basis of change in Fermi energy level of the host matrix vanadium, the strong bonding nature of V-Al in the alloy and increased activity of hydrogen due to aluminum in the alloy.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Sanjay Kumar, Sagar Sonak, Nagaiyar Krishnamurthy,