Influence of alloying on the electron momentum density in the Cu-Ni system

Abstract

We report on the measurement of the three-dimensional electron momentum density ͑EMD͒ of a 22 nm Cu/22 nm Ni sandwich foil and of a Cu 0.50 Ni 0.50 alloy film with the same thickness, which was obtained from an identical sandwich by interdiffusion. The EMD's were measured by coincident detection of a Compton scattered photon with its recoil electron. The experiments were performed at the High-Energy beamline of the European Synchrotron Radiation Facility. The experimentally observed small change of the EMD due to alloying is reproduced by the Korringa-Kohn-Rostoker coherent-potential approximation scheme ͓Benedek et al.

Three-dimensional electron momentum densities of solids

“…non-coincident Compton scattering experiments on Cu-Ni single crystals, absolute values of experimental CPs are difficult to interpret due to the presence of a background contribution of uncertain origin. The solid line in figure 12 represents KKR-CPA theory [46,53]. In view of the smallness of the effect, a reasonable agreement between theory and experiment is observed.…”

“…In this section we will report on the influence of alloying by comparing the EMD of Cu 0.50 Ni 0.50 with those of its pure constituents [46]. The electronic structure of this 3d transition-metal solid-solution alloy has received extensive attention.…”

Recent Results from (γ, ϱγ) and Compton Spectroscopy

“…Neither data processing like a deconvolution procedure accompanied by frequency filtering nor background subtraction has been applied to our data. The solid line in Figure 8.5 represents KKR-CPA theory [20,22]. In view of the smallness of the effect a reasonable agreement between theory and experiment is observed.…”

“…In this chapter we will report on the influence of alloying by comparing the EMD of Cu 0.50 Ni 0.50 with those of its pure constituents [20]. The electronic structure of this 3d transition-metal solid-solution alloy has received extensive attention.…”

Electron momentum density in Ni75Cu25and Ni75Co25disordered alloys: a high-resolution Compton-scattering study

“…In the context of this work it is worth mentioning an interesting study of the Ni-Cu system by Metz et al [28], who observed directly the effects of alloying close to the Fermi energy, using the (γ , eγ ) coincidence technique. Their observations generally agree with the predictions of KKR-CPA theory; however, it is difficult to compare them directly with our results, mainly because of the very different composition of the alloys studied.…”