Hydrogen vibrations in austenitic fcc --- steels

¹ Hahn-Meitner-Institut - 14109 Berlin, Germany
² Technische Universität Darmstadt - 64289 Darmstadt, Germany
³ Institut Max von Laue-Paul Langevin - 38042 Grenoble Cedex 9, France
⁴ Institute for Metal Physics - 252142 Kiev, Ukraine
⁵ Ecole Nationale Supérieure des Mines de Saint-Etienne 42023 Saint-Etienne Cedex 2, France

Received: 7 October 2002
Accepted: 30 April 2003

Abstract

By neutron spectroscopy, we studied vibrations of interstitials in two austenitic fcc steels ( and ) doped with 0.37 and 0.33 at% . The band modes, in which vibrates with its metal neighbours, cause a weak intensity in the energy range of the acoustic vibrations of the -free steels. The energies of the fundamental and the twofold local-mode excitations, in which vibrates against its metal neighbours, were and , respectively. The respective peaks in the spectra were broadened because the metal neighbours of , and thus its vibrational energies, vary from interstitial site to interstitial site. The above energy values support an occupation of octahedral interstitial sites.