Spin‐Polarized Compton Profile of Nickel

Abstract

The expression for the spin-polarized Compton profile is calculated using relativistic corrections in a nonrelativistir time-dependent perturbation theory. The spin polarization of the Compton profile for ferromagnetic materials can be measured by circularly polarized X-rnya. The calculated spin-polarized Compton profile of nickel is presented. The anisotropic profiles and the isotropic one are considered. The curves show a characteristic shape caused by n positive spin polarizntion of the d-electrons and a negative one of the s,p-electrons.Dcr Ausdruck fur das spinpolarisierte Comptonprofil wird bereclinet unter Verwendung relativistischer Korrekturen in einer nichtrelativistischen, zeitabllangigen Storungstheorie. Man kann die Spinpolarisation des Comptonprofils fiir ferromagnetische Mnterialien mit zirkulnr polarisierten Rontgenstrnhlen messen. Dns berechnetc spinpolnrisierte Comptonprofil von Nickel wird vorgelegt. Die aniBotropen Profile nnd daa isotropc werden betrachtet. Die K~irven zeigen eine charakteriatische Form, die durch eine positive Spinpolnrisation der d-Elektronen und eine negAtive der s,p-Elektronen verursarht wird.

Magnetic Compton profiles of disordered Fe0.5Ni0.5 and ordered FeNi alloys

“…Accordingly, the magnetic Compton interference term is the MCP obtained using the Green's function of Eq. (7). Note that the Compton interference function can be an alloy-type non-diagonal or diagonal depending on the occupation of the q(q ′ )-sites.…”

“…The computed Magnetic Compton Profile (MCP) spectra for Ni [7][8][9][10][11][12][13][14][15] and Fe 9,12,16,17 have been previously reported in the literature. The analysis of spectra covers the aspects of multiple scattering, core contribution, relativistic effects and electronic correlations.…”

“…Along the [111] direction prominent features of the MCP for Fe and Ni are (i) the negative polarization of s− and p−bands at low momentum, (ii) dips in the MCP profiles near p z = 0 a.u., and the (iii) periodic features due to the Umklapp processes at momenta p = k ± n G, where G is the reciprocallattice vector and n ∈ Z. Generally, the theory overestimates the MCP spectra near p z = 0 irrespective of the band-structure method used in the Density Func-tional Theory (DFT) calculations [7][8][9][10][11]16,17 . This discrepancy have been attributed to the inadequate treatment of the electron-electron correlations in the Local Density Approximation (LDA) or its gradient corrected (GGA) type independent-particle-models for the exchange correlations of DFT.…”

Spin density in ferromagnetic nickel: a magnetic Compton scattering study

“…Band-theoretical predictions of the MCPs for Ni have previously been made, within the LSDA, by a number of authors [1,[8][9][10]. Although we compare various sets of published data, we will concentrate on the FLAPW data of Kubo and Asano [1], and our own LMTO calculations.…”

“…The spin-dependent electron momentum density distribution has been calculated using various methods [1,[8][9][10], although only within the LSDA. It is the one-dimensional (1D) projection of this distribution which can be measured experimentally by Compton scattering, as described in section 2, and magnetic Compton scattering can provide a sensitive method of investigating the spin-dependent properties.…”