Structural instability in the B2-type ordered alloys Zr (Ru,Rh) and Zr (Ru,Pd)

The exceptional toughness and wear resistance of the alloy Zr50Pd35Ru15 apparently derives from a growing instability in the B2 phase as Pd atoms substitute for Ru atoms on the ordered lattice sites. A similar behavior occurs when Rh atoms are the substituent. The growing instabilities are accompanied by a softening of the alloys, by the onset of superconductivity and by an improved ductility partly due to stress induced transformations. The origin of this behavior can be traced to an increasing electronic density of states in the band structures of these alloys and a softening of the lattice phonons as revealed by low-temperature specific heat measurements. Published by Elsevier B.V.