Vibration Effects on the Structural Stability of Al-Ti Intermetallics by First-principles Calculations

Hui Zhang and Shaoqing Wang Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

摘 要：The structural stability of the intermetallics AlTi3,Al2Ti,Al3Ti4 and Al3Ti in the Al-Ti system has been investigated using density functional theory（DFT） and density functional perturbation theory（DFPT）.The calculated ground-state convex hull is in agreement with the experimental researches.Al3Ti4（hP7） is metastable at 0 K and may be stabilized as the temperature increases due to the effects of the vibration entropy.For Al2Ti,r-Al2Ti is stable at 0 K and h-Al2Ti is stabilized by the vibration entropy at high temperatures.Al3Ti（tI16） is unstable considering vibration effects and Al3Ti（tI8） is the most stable structure at 0 K.

关键词：