On the question of stability and disorder in icosahedral aluminum – transition metal alloys

Abstract

Through an X-ray diffraction and thermal analysis investigation of melt spun Al – transition metal (Al–TM) alloys, we report the formation of a highly stable and well-ordered pure icosahedral (i) phase in Al80TMl20−xTM2x(TM1 = V, Cr; TM2 = Fe, Co). The superior i-phase formation over that in the binary Al–TM alloys is interpreted in terms of the distribution of TM sites known to exist in this phase. A comparison of the i-phase formation ranges indicates the presence of two distinct classes of TM sites and a strong interaction between adjacent TM sites.