Neutron diffraction on antiferromagnetic ordering in single-crystal BaFe2As2

• Published in: arXiv.org
• Main Authors: Y Su, Link, P, Schneidewind, A, Wolf, Th, Adelmann, P, Xiao, Y, Meven, M, Mittal, R, Rotter, M, Johrendt, D, Brueckel, Th, Loewenhaupt, M
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.12.2008
• Subjects: Antiferromagnetism; Crystal growth; Crystal structure; Diffraction; Group 5A compounds; Iron; Magnetic moments; Magnetic structure; Neel temperature; Neutron diffraction; Neutron flux; Neutrons; Orthorhombic phase; Phase transitions; Physics - Strongly Correlated Electrons; Physics - Superconductivity; Single crystals; Tin; Wave propagation
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0807.1743

Neutron diffraction experiments have been carried out on a Sn-flux grown BaFe2As2 single crystal, the parent compound of the A-122 family of FeAs-based high-Tc superconductors. A tetragonal to orthorhombic structural phase transition and a three dimensional long-range antiferromagnetic ordering of the iron moment, with a unique magnetic propagation wavevector k = (1, 0, 1), have been found to take place at ~90 K. The magnetic moments of iron are aligned along the long a axis in the low temperature orthorhombic phase (Fmmm with b<a<c). Our results thus demonstrate that the magnetic structure of BaFe2As2 single crystal is the same as those in other A-122 iron pnictides compounds. We argue that the tin incorporation in the lattice is responsible for a smaller orthorhombic splitting and lower Neel temperature T_N observed in the experiment.