Soft X‐ray spectra in Nb‐Mo alloy

Abstract

Soft X-ray spectra (SXS) a r e largely used to probe the band structure of metals and alloys /l/. Recently a number of standard band calculations have been

Electronic structure of disordered Nb - Mo alloys studied using the charge-self-consistent Korringa - Kohn - Rostoker coherent potential approximation

“…We note first that our results for the DOSs for Nb and Mo are in good accord with earlier KKR calculations of [50], and the LCGO computations of [16,17]. In Nb-Mo alloys also our densities of states as well as the site-decomposed densities of states are more or less similar to the various published results [18,19], some differences notwithstanding. Here we give an overview of the salient features of the electronic spectrum with the help of figures 4-7 (see [51] for details).…”

“…In connection with superconductivity, the composition dependence of λ and T c in Nb-Mo is reported in [11] and [15]. A note may also be made of the thermomodulation and soft x-ray studies [19,20], and of the temperature coefficient of the elastic shear constant, C 44 , and the Grüneisen parameter [28]. The latter work shows that the elastic constants behave anomalously in Nb 1−x Mo x around x = 0.4, and provides an interesting example of effects that can arise from the interplay between changes in the electron-phonon interactions and the FS topology in alloys.…”

“…We turn now to the FSs of disordered Nb-Mo alloys with reference to figures 2(b)-2(d) and tables 3-5 [19][20][21][22][23][24][25][26][27]. The evolution of various FS sheets of Nb upon adding Mo is considered first.…”

“…Here we present highly precise all-electron fully charge-self-consistent KKR-CPA results for Nb 1−x Mo x over the entire composition range, including pure Nb and Mo limits, all computations having been carried out within very similar frameworks. Many computations on Nb-Mo alloys within the virtual-crystal approximation (VCA), the average t-matrix approximation (ATA), as well as the CPA have been reported in the literature, including a discussion of the Compton, positron annihilation 2D angular correlation (2D-ACAR), and soft x-ray spectra, and the superconducting properties [18][19][20][21][22][23][24][25][26][27]. All of the previous computations are however non-self-consistent, being based on a variety of prescriptions for obtaining the crystal potential; to our knowledge, full charge self-consistency has not been achieved in any of the earlier work on the Nb-Mo system.…”

“…In contrast, the present results, being fully self-consistent, constitute unique predictions of the theory, and provide a more satisfactory testbed for confronting the underlying one-electron picture with experiment. We focus on the evolution of the FS of Nb 1−x Mo x and present, for the first time to our knowledge, changes in the shapes and radii of various FS sheets in quantitative detail, whereas much of the existing literature [18][19][20][21][22][23] in this regard is rather qualitative. The nature of electronic states at the Fermi energy is delineated clearly.…”