Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1624373 | Journal of Alloys and Compounds | 2008 | 6 Pages |
Abstract
The standard Gibbs energy of formation, ÎfGT°, of MgLa in the temperature range from near absolute 0 to 525 K were determined by calorimetry. The heat capacities, Cp, from 2 K to 525 K were measured by the relaxation method and DSC. Also, a thermal anomaly at 5.9 K, which appeared to be a superconductive phase transition, was found in the obtained Cp values. The ÎfGT°(MgLa) values were determined by combining the Cp data with the standard enthalpy of formation at 298 K which was measured by the Calvet-type calorimeter using hydrochloric acid solution. From 2 to 300 K, the ÎfGT° increases gradually, and it can be evaluated as a linear function of temperature above 300 K as follows:ÎfGT°(MgLa)(kJmolâ1)=â39.236â6.9832Ã10â3T+2.1016Ã10â3TlogT+1.9114Ã10â5T2â0.81004Tâ1±7.40(2â300K),ÎfGT°(MgLa)(kJmolâ1)=â41.100+9.9974Ã10â3T±7.40(300â525K).This result is expected to be useful as basic thermodynamic data of Mg-based alloys.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Masao Morishita, Hiroaki Yamamoto, Ai Onoue, Yasutomo Matsumoto,