Document Type

Article

Publication Version

Published Version

Publication Date

11-1-2013

Journal or Book Title

Physical Review B

Volume

88

Issue

18

First Page

184515

DOI

10.1103/PhysRevB.88.184515

Abstract

In BaFe2As2, structural and magnetic planar defects begin to proliferate below the structural phase transition, affecting descriptions of magnetism and superconductivity. We study, using density-functional theory, the stability and magnetic properties of competing antiphase and domain boundaries, twins and isolated nanotwins (twin nuclei), and spin excitations proposed and/or observed. These nanoscale defects have a very low surface energy (22–210 m Jm−2), with twins favorable to the mesoscale. Defects exhibit smaller moments confined near their boundaries—making a uniform-moment picture inappropriate for long-range magnetic order in real samples. Nanotwins explain features in measured pair distribution functions so should be considered when analyzing scattering data. All these defects can be weakly mobile and/or can have fluctuations that lower assessed “ordered” moments from longer spatial and/or time averaging and should be considered directly.

Comments

This article is from Phys. Rev. B 88, 184515 (2013), doi:10.1103/PhysRevB.88.184515. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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