In-plane Uniaxial Pressure-Induced Out-of-Plane Antiferromagnetic Moment and Critical Fluctuations in BaFe2As2

Published

November 12, 2020

Author(s)

Panpan Liu, Mason L. Klemm, Long Tian, Xingye Lu, Yu Song, David W. Tam, Karin Schmalzl, J. T. Park, Yu Li, Guotai Tan, Yixi Su, Frederic Bourdarot, Yang Zhao, Jeffrey W. Lynn, Robert J. Birgeneau, Pengcheng Dai

Abstract

A small in-plane external uniaxial pressure has been widely used as an effective method to acquire single domain iron pnictide BaFe₂As₂, which exhibits twin-domains without uniaxial strain below the tetragonal-to-orthorhombic structural (nematic) transition temperature T_s. 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 TN (< T_s) and create in-plane resistivity anisotropy above T_s. Here we use neutron polarization analysis to show that such a strain on BaFe₂As₂ also induces a static or quasi-static out-of-plane (c-axis) AF order and its associated critical spin fluctuations near TN/Ts. Therefore, uniaxial pressure necessary to detwin single crystals of BaFe₂As₂ actually rotates the easy axis of the collinear AF order near T_N/T_s, and such effect due to spin-orbit coupling must be taken into account to unveil the intrinsic electronic/magnetic properties of the system.

Citation

Nature Communications

Volume

11

Issue

1

Pub Type

Journals

Keywords

Iron Superconductor, uniaxial pressure, magnetic structure, polarized neutron diffraction, critical fluctuations

Citation

Liu, P. , Klemm, M. , Tian, L. , Lu, X. , Song, Y. , Tam, D. , Schmalzl, K. , Park, J. , Li, Y. , Tan, G. , Su, Y. , Bourdarot, F. , Zhao, Y. , Lynn, J. , Birgeneau, R. and Dai, P. (2020), In-plane Uniaxial Pressure-Induced Out-of-Plane Antiferromagnetic Moment and Critical Fluctuations in BaFe₂As₂, Nature Communications (Accessed April 26, 2024)