Low-energy planar magnetic defects in BaFe2As2: Nanotwins, twins, antiphase, and domain boundaries

TitleLow-energy planar magnetic defects in BaFe2As2: Nanotwins, twins, antiphase, and domain boundaries
Publication TypeJournal Article
Year of Publication2013
AuthorsKhan SN, Alam A, Johnson DD
Journal TitlePhysical Review B
Volume88
Pages184515
Date Published11
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000327933600008
Keywordspnictides, superconductivity
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.

URL<Go to ISI>://WOS:000327933600008
DOI10.1103/PhysRevB.88.184515