Quantum-Many-Body Intermetallics: Phase Stability of Fe$_3$Al and   Small-Gap Formation in Fe$_2$VAl
  Various intermetallic compounds harbor subtle electronic correlation effects. To elucidate this fact for the Fe-Al system, we perform a realistic many-body investigation based on the combination of density functional theory with dynamical mean-field theory in a charge self-consistent manner. A better characterization and understanding of the phase stability of bcc-based D0$_3$-Fe$_3$Al through an improved description of the correlated charge density and the magnetic-energy is achevied. Upon replacement of one Fe sublattice by V, the Heusler compound Fe$_2$VAl is realized, known to display bad-metal behavior and increased specific heat. We here document a charge-gap opening at low temperatures in line with previous experimental work. The gap structure does not match conventional band theory and is reminiscent of (pseudo)gap charateristics in correlated oxides. 
Oleg Kristanovski, Raphael Richter, Igor Krivenko, Alexander I.   Lichtenstein, Frank Lechermann
cond-mat.mtrl-sci cond-mat.str-el