Study of the interstitial solid solutions of transition metals by inelastic incoherent neutron scattering

摘要

A high-flux IBR-2 reactor makes it possible to measure the local modes (LMs) of p elements (O, N, and Q in transition metals with concentrations of similar to 1 at. % using inelastic incoherent neutron scattering IINS). The large sizes of these atoms cause strong repulsion in IS octahedra, which results in strong distortions at the IS site of a metal lattice and the formation of split LMs of metal atoms, i.e., the nearest neighbors of ISs, clustering of ISs, and other phenomena characteristic of radiation defects rather than of hydrogen impurity, which has been studied previously. The interaction of IS p atoms and substitutional atoms also differs significantly from an interaction of substitutional atoms with hydrogen. The LMs of p elements change their position and width very little during their interaction with undersized substitutional atoms, i.e., during preferential deformation interactions. Purely chemical interactions of p elements with alloying substitutional elements have only been observed in iron-based alloys. A model that allows an estimation of the contribution of the deformation interaction to changes in the LMs of IS atoms during the formation of a defect cluster is proposed. This model accounts for lattice relaxation at the IS site and offers an explanation of the results previously obtained using the IINS method.