Magnetic groundstate and Fermi surface of bcc Eu

TL;DR

This paper investigates the magnetic ground state and Fermi surface of bcc Eu using advanced electronic structure calculations, revealing an incommensurate spin-spiral ground state linked to Fermi surface nesting.

Contribution

It demonstrates the magnetic coupling mechanisms in bcc Eu and uncovers the connection between the spin-spiral ground state and Fermi surface nesting, a novel insight.

Findings

Ground state is an incommensurate spin-spiral consistent with experiments.

Magnetic coupling primarily via intra-atomic exchange and RKKY mechanism.

Spin-spiral linked to a previously unnoticed Fermi surface nesting feature.

Abstract

Using spin-spiral technique within the full potential linearized augmented-plane-waves (LAPW) electronic structure method we investigate the magnon spectrum and N\'eel temperature of bcc Eu. Ground state corresponding to an incommensurate spin-spiral is obtained in agreement with experiment and previous calculations. We demonstrate that the magnetic coupling is primarily through the intra-atomic $f-s$ and $f-d$ exchange and Ruderman-Kittel-Kasuya-Yosida mechanism. We show that the existence of this spin-spiral is closely connected to a nesting feature of the Fermi surface which was not noticed before.