Local structural variation as source of magnetic moment reduction in BaFe2As2

TL;DR

This study reveals that local lattice variations, likely due to nano-twins, in BaFe2As2 contribute to the reduction of magnetic moments, explaining discrepancies between observed and theoretical values.

Contribution

It introduces the concept that local structural variations, specifically nano-twins, influence magnetic properties in BaFe2As2, providing new insight into magnetic moment reduction.

Findings

Local lattice variations are significant at short distances.

Nano-twins are prevalent and affect magnetic alignment.

Structural variations partly explain magnetic moment discrepancies.

Abstract

We report time-of-flight neutron powder diffraction results on stoichiometric BaFe2As2. Pair distribution function analysis shows that the orthorhombic distortion in the a-b plane at short distances are significantly different from the average lattice distortion, indicating local variations in the lattice at the short-range. We propose that this local variation reflects a high density of nano-twins, short-ranged structures which locally affect the magnetic alignment. This results suggests that the discrepancies between the observed and calculated magnetic moments in BaFe2As2 arise partly from short-ranged variation of the lattice in the a-b plane.