Relativistic spin-polarized single-site scattering theory

Abstract

Relativistic spin-polarized scattering theory is discussed and the relevant radial Dirac equations for an electron in a potential with a magnetic field component are derived. The full solution to the coupled Dirac equations treating spin-orbit coupling and spin polarization on an equal footing is found and, by matching these wavefunctions at the muffin-tin radius, the scattering amplitudes and phase shifts are calculated. The interpretation of these results gives a pictorial view of the interplay between spin-orbit coupling and spin polarization. New coupling between states is observed due to the removal of previously used approximations. The magnitude of this coupling throws doubt on some earlier calculations of magnetocrystalline anisotropy energies. A scattering analogue to the generalized Zeeman effect is also described.

Multiple-scattering theory of x-ray magnetic circular dichroism: Implementation and results for the ironKedge

“…¿From the formal point of view fully relativistic programs require a coupling of an infinity of different l values due to the magnetic field. 43 Up to now, the coupling between l and l ± 2 was neglected, which limits the maximum possible value of l. 44 In our approach, this coupling is made consistently with 1/c through the expansion process.…”

Electronic structure and magnetic properties of random alloys: Fully relativistic spin-polarized linear muffin-tin-orbital method

“…Since the coupling between solutions with different quantum numbers l corresponds to the so-called magnetic spin-orbit interaction "ϰc Ϫ2 r Ϫ1 ͓dB(r)/dr͔L•S…, 25 this term is usually neglected as it is of order c Ϫ2 and since B(r) varies only slowly with respect to r. However, quite recently, Jenkins and Strange 26 pointed out that this approximation might lead to incorrect results for magnetocrystalline anisotropies. In the present work the approximation ⌬l ϭ0 is assumed.…”

Influence of the Molecular Groups Ordering on Structural Phase Transitions in (NH4)2WO2F4 Crystal

“…The spectral changes in the range of the ammonium stretching vibrations with temperature increasing are given in Figure (panels a and b). Large linewidths, particularly in the range of 2500–3500 cm –1 , corresponding to the internal stretching vibrations of the ammonium ion, can be due to both the influence of the well-known anharmonicity of NH 4 + ion vibrations and the orientational disordering of ammonium sublattices . New lines arise after decreasing temperature below T = 190 K. The phenomena observed can be accounted for by the fact that cooling the crystal below the phase transition temperature results in the ordering of the ammonium groups.…”