title: Spin waves and magnetic exchange interactions in insulating Rb(0.89)Fe(1.58)Se(2).
abstract: The parent compounds of iron pnictide superconductors are bad metals with a collinear antiferromagnetic structure and Néel temperatures below 220 K. Although alkaline iron selenide A(y)Fe(1.6+x)Se(2) (A=K, Rb, Cs) superconductors are isostructural with iron pnictides, in the vicinity of the undoped limit they are insulators, forming a block antiferromagnetic order and having Néel temperatures of roughly 500 K. Here we show that the spin waves of the insulating antiferromagnet Rb(0.89)Fe(1.58)Se(2) can be accurately described by a local moment Heisenberg Hamiltonian. A fitting analysis of the spin wave spectra reveals that the next-nearest neighbour couplings in Rb(0.89)Fe(1.58)Se(2), (Ba,Ca,Sr)Fe(2)As(2), and Fe(1.05)Te are of similar magnitude. Our results suggest a common origin for the magnetism of all the Fe-based superconductors, despite having different ground states and antiferromagnetic orderings.
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
authors.forename: Miaoyin
authors.initials: M
authors.lastname: Wang
authors.forename: Chen
authors.initials: C
authors.lastname: Fang
authors.forename: Dao-Xin
authors.initials: DX
authors.lastname: Yao
authors.forename: GuoTai
authors.initials: G
authors.lastname: Tan
authors.forename: Leland W
authors.initials: LW
authors.lastname: Harriger
authors.forename: Yu
authors.initials: Y
authors.lastname: Song
authors.forename: Tucker
authors.initials: T
authors.lastname: Netherton
authors.forename: Chenglin
authors.initials: C
authors.lastname: Zhang
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Stone
authors.forename: Wei
authors.initials: W
authors.lastname: Tian
authors.forename: Jiangping
authors.initials: J
authors.lastname: Hu
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Dai
mesh_terms: D002627:Chemistry, Physical; D018360:Crystallography, X-Ray; D004553:Electric Conductivity; D004583:Electrons; D005296:Ferrous Compounds / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008280:Magnetics / Q000379:methods*; D015394:Molecular Structure; D012413:Rubidium / Q000737:chemistry; D012643:Selenium / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics
chemical_list: D005296:Ferrous Compounds; D007501:Iron; D012643:Selenium; D012413:Rubidium