STRUCTURAL PHASE STABILITY OF Ti3Al UNDER HIGH PRESSURE

Abstract

Recently, the structural stability of the high temperature structural intermetallic Ti 3 Al has been investigated experimentally and a transition from the DO 19 to the DO 24 structure has been reported. We have performed band structure calculations as a function of reduced volume by tight binding linear muffin-tin orbital (TBLMTO) method to look into these transitions to understand their mechanisms in terms of its electronic structure. The mechanism of the DO 19 to the DO 24 structure is understood to be due to shifting of the Fermi energy into a valley in the density of states curve, thereby driving the system to a more stable structure.