Collinear antiferromagnetism in trigonal SrMn2As2 revealed by single-crystal neutron diffraction. (15th November 2016)

• Record Type: Journal Article
• Authors: Das, Pinaki; Sangeetha, N S; Pandey, Abhishek; Benson, Zackery A; Heitmann, T W; Johnston, D C; Goldman, A I; Kreyssig, A
• Is Part Of: Journal of physics. Volume 29:Number 3(2017)
• Publication Date: 2016-11-15
• Subjects: neutron diffraction -- magnetic structure -- corrugated honeycomb structure -- ordered magnetic moment -- quasi-two-dimensional magnetic correlation; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/29/3/035802
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Iron pnictides and related materials have been a topic of intense research for understanding the complex interplay between magnetism and superconductivity. Here we report on the magnetic structure of SrMn2 As2 that crystallizes in a trigonal structure ( P 3 ̄ m 1 ) and undergoes an antiferromagnetic (AFM) transition at T N = 118 ( 2 ) K. The magnetic susceptibility remains nearly constant at temperatures T ⩽ T N with H ∥ c whereas it decreases significantly with H ∥ a b . This shows that the ordered Mn moments lie in the a b plane instead of aligning along the c -axis as in tetragonal BaMn2 As2 . Single-crystal neutron diffraction measurements on SrMn2 As2 demonstrate that the Mn moments are ordered in a collinear Néel AFM phase with 180 ∘ AFM alignment between a moment and all nearest neighbor moments in the basal plane and also perpendicular to it. Moreover, quasi-two-dimensional AFM order is manifested in SrMn2 As2 as evident from the temperature dependence of the order parameter.