کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1278860 | 1497651 | 2008 | 10 صفحه PDF | دانلود رایگان |
High-energy ball milling has been shown to decrease the release temperature, increase the reaction kinetics, and lower the enthalpy of formation of metal hydrides in certain cases. This paper discusses several potential mechanisms for the reduction of the enthalpy of formation. Although the increased surface and grain boundary energy could play a role in reducing the enthalpy of formation, the predicted magnitude is too small to account for experimental observations. Structural deformation and the associated volume change provide another mechanism for the change in this thermodynamic property. We employed three equations of state models to characterize the excess energy present in the deformed regions and found that the excess volume provides a plausible explanation for the experimentally observed change in thermodynamic properties.
Journal: International Journal of Hydrogen Energy - Volume 33, Issue 15, August 2008, Pages 4122–4131