PHASE TRANSITIONS IN COMPOUNDS WITH THE C-15 STRUCTURE.

The temperature dependences of the parameters of elasticity were determined for compounds with the C-15 structure. The dependences of the phase transition temperatures on the stoichiometry of ZrV//2// minus //y and on the composition of Zr//1// minus //xHf//xV//2 alloys were obtained. A strong frequency dispersion of the velocity of longitudinal sound observed in HfV//2 was attributed to a transition of this compound to a state with an incommensurate charge density wave.