Electronic structure of B2-type Ti–(50− x)Ni–xFe and Ti–(50− x)Pd–xFe alloys exhibiting incommensurate diffuse scattering

Abstract: We have calculated the electronic structure of B2-type Ti–(50− x)Ni–xFe (0≤ x ≤28at.%) and Ti–(50− x)Pd–xFe (0≤ x ≤22at.%) alloys in order to understand the origin of diffuse scattering appearing in these systems, and the stability of the B2-type structure. For both systems, the Fermi surface of each alloy shows nesting with a sharp peak in the generalized susceptibility χ( q ) at a nesting vector of q n =[ζ n ζ n 0]2π/a. The value of ζ n of the peak position decreases linearly as the Fe content increases. In addition, the peak of χ( q ) decreases as the Fe content increases except for Ti–(50− x)Ni–xFe with x ≤4at.%. These results suggest that the position of diffuse scattering shifts towards its nearest fundamental reflection of the B2-phase as the Fe content increases and that the stability of the B2-phase increases with increasing Fe content. These suggestions are in good agreement with experimental results reported until now. [Copyright &y& Elsevier]