Abstract
The difference in vibrational entropy between disordered and D0 3 -ordered Fe 3 Al was measured by calorimetry to be (0.10 ± 0.03) k B /atom at high temperatures, with the ordered alloy having the lower vibrational entropy. Analysis of the vibrational modes of the ordered and disordered alloys with a Born-von Karman model showed that the lower vibrational entropy of the ordered alloy originates from high-frequency optical modes involving the vibration of the aluminum-rich sublattice. These modes are consistent with the large changes in local vibrational amplitudes of Al atoms upon ordering that were measured by extended electron energy loss fine structure spectrometry.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
