2012/11/30 by Miaoyin Wang, Xingye Lu, R. A. Ewings +8 · 2 citations
Materials Science · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Ferromagnetism #Iron-based superconductors research #Magnetic field #Magnetization #Materials science #Mott insulator #Néel temperature #Paramagnetism #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Rare-earth and actinide compounds #Spin (aerodynamics) #Spin wave #Thermodynamics #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.87.064409
published in Physical Review B 87(6) (American Physical Society) · 5 pages, 4 figures
arxiv created 2012/11/30 · openalex publication_date 2013/02/08 · arxiv updated 2013/02/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use neutron scattering to study temperature-dependent spin excitations in insulating antiferromagnetic (AF) Rb0.8Fe1.6Se2. In the low-temperature AF state, spin waves can be accurately described by a local moment Heisenberg Hamiltonian. On warming to around the N'eel temperature of TN=500 K, low-energy (E<30 meV) paramagnetic spin excitations form Lorentzian-like quasielastic peaks centered at the AF wave vectors associated with spin waves, while high-energy (E>50 meV) spin excitations become heavily damped. Upon further warming to above the structural distortion temperature of Ts=524 K, the entire paramagnetic excitations become overdamped. These results suggest that AF Rb0.8Fe1.6Se2 is not a copper-oxide--like Mott insulator and has less electron correlations compared with metallic iron pnictides and iron chalcogenides.