In-plane uniaxial pressure-induced out-of-plane antiferromagnetic moment and critical fluctuations in BaFe<sub>2</sub>As<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33184278.
- Also identified by DOI 10.1038/s41467-020-19421-5 and PMC identifier 7665052.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
A small in-plane external uniaxial pressure has been widely used as an effective method to acquire single domain iron pnictide BaFe<sub>2</sub>As<sub>2</sub>, which exhibits twin-domains without uniaxial strain below the tetragonal-to-orthorhombic structural (nematic) transition temperature T<sub>s</sub>. Although it is generally assumed that such a pressure will not affect the intrinsic electronic/magnetic properties of the system, it is known to enhance the antiferromagnetic (AF) ordering temperature T<sub>N</sub> ( < T<sub>s</sub>) and create in-plane resistivity anisotropy above T<sub>s</sub>. Here we use neutron polarization analysis to show that such a strain on BaFe<sub>2</sub>As<sub>2</sub> also induces a static or quasi-static out-of-plane (c-axis) AF order and its associated critical spin fluctuations near T<sub>N</sub>/T<sub>s</sub>. Therefore, uniaxial pressure necessary to detwin single crystals of BaFe<sub>2</sub>As<sub>2</sub> actually rotates the easy axis of the collinear AF order near T<sub>N</sub>/T<sub>s</sub>, and such effects due to spin-orbit coupling must be taken into account to unveil the intrinsic electronic/magnetic properties of the system.