ELECTRONIC-STRUCTURE AND MARTENSITIC-TRANSFORMATION IN A ZRRH ALLOY

Experiments have revealed that equiatomic ZrRh alloy exhibits, upon co oling or heating, a structural transformation of the martensitic type from B2 to B19' and vice versa, involving a hysteresis of the order 20 0 degrees C and a shape memory effect. On the basis of the electronic structure calculation for the B2 phase of the ZrRh alloy, it is sugges ted that a reason for the structural instability of this ZrRh phase po ssessing a high-symmetry can be presence of a flat region near the Fer mi level in the dispersion law.