The magnetic form factor of iron in SrFe2As2

TL;DR

This study combines neutron diffraction and DFT calculations to determine the magnetic form factor of iron in SrFe2As2, revealing its similarity to bcc iron and the influence of hybridization and geometry on spin density anisotropy.

Contribution

It provides the first detailed comparison of the experimental and theoretical magnetic form factor of iron in SrFe2As2, highlighting the insensitivity of the form factor shape to Fe-As distance.

Findings

Form factor closely resembles that of bcc iron

Calculated magnetic moment sensitive to Fe-As distance

Spin density shows anisotropy due to hybridization

Abstract

The iron magnetic form factor in SrFe2As2 has been determined by neutron diffraction and by density functional theory (DFT). As noted previously, the magnitude of the calculated moment using DFT is sensitive to the Fe-As distance. However, the shape of the calculated form factor is practically insensitive to the Fe-As distance, and further we show that the form factor closely resembles that of bcc iron, and agrees well with experiment. The spin density exhibits some anisotropy due to geometry and As hybridization.