Acoustic investigations of the ZrV2-H system

Elastic modulus and internal friction of the ZrV2Hx system have been measured by the method of low-frequency acoustics (∼1 kHz) in a wide range of hydrogen concentrations (0 ≤ x ≤ 6) and temperatures (65 K < T < 300 K). It is established that an increase of the hydrogen concentration shifts the structural phase transformation from the rhombohedral to the cubic phase of the ZrV2 compound towards high temperatures and leads to its suppression. An anomaly of the elastic modulus in the concentration range 0.7 < x ≤ 6 with a corresponding peak of the internal friction was detected at a temperature of ∼200 K, characteristic of the phase transition. The relaxation peak of the internal friction observed above 200 K is caused by dissipation of elastic energy on interphase boundaries.