The anelastic relaxation due to the reorientation of the ZrH pair has been measured in two Nb single crystals at low H and Zr contents. The two crystals were oriented with the longer dimension along the [100] and [111] directions, and were excited in their extensional, torsional and flexural modes. The observed dissipation between 50 and 200 K consists of at least two peaks. One of them is not observed under [100] torsional and [111] extensional vibrations, and this is interpreted as due to the redistribution of H among four-site tunnel systems over the faces of the cube containing the Zr atom. The other peak is predominant and is always observed, implying the occupation of additional sites.
Anelastic relaxation of H trapped by Zr in Nb single crystals
F Cordero;
1994
Abstract
The anelastic relaxation due to the reorientation of the ZrH pair has been measured in two Nb single crystals at low H and Zr contents. The two crystals were oriented with the longer dimension along the [100] and [111] directions, and were excited in their extensional, torsional and flexural modes. The observed dissipation between 50 and 200 K consists of at least two peaks. One of them is not observed under [100] torsional and [111] extensional vibrations, and this is interpreted as due to the redistribution of H among four-site tunnel systems over the faces of the cube containing the Zr atom. The other peak is predominant and is always observed, implying the occupation of additional sites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
