Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9804004 | Journal of Alloys and Compounds | 2005 | 6 Pages |
Abstract
EMF measurements on silicon concentration cell were carried out using lithium silicate electrolyte in the temperature range 1300-1500 K. Using the EMF-temperature relations obtained, the standard free energies of formation for W5Si3 and WSi2 have been calculated as functions of temperature: ÎG0(W5Si3) (kJ molâ1) = â128.6 â 0.0132 (T (K)) ± 0.42 and ÎG0(WSi2) (kJ molâ1) = â98.5 + 0.0095 (T (K)) ± 0.15, respectively. Combining the results with thermodynamic data, the standard enthalpies of formation for silicides at 298 K have been obtained as ÎH0(W5Si3, 298) (kJ molâ1) = â133 ± 25 and ÎH0(WSi2, 298) (kJ molâ1) = â82 ± 6, respectively. A new eutectoid reaction W5Si3 â W + WSi2 occurring around 700 K is suggested in W-Si binary system.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Hiroyasu Fujiwara, Yukitomi Ueda, Alok Awasthi, Nagaiyar Krishnamurthy, Sheo Parkash Garg,