Paramagnetic spin excitations in insulating Rb$_{0.8}$Fe$_{1.6}$Se$_2$

Miaoyin Wang; Xingye Lu; R. A. Ewings; Leland W. Harriger; Yu Song; Scott V. Carr; Chunhong Li; Rui Zhang; Pengcheng Dai

doi:10.1103/PhysRevB.87.064409

paper

Paramagnetic spin excitations in insulating Rb $_{0.8}$ Fe $_{1.6}$ Se $_{2}$

arXiv:1211.7328 · doi:10.1103/PhysRevB.87.064409

Abstract

We use neutron scattering to study temperature dependent spin excitations in insulating antiferromagnetic (AF) Rb $_{0.8}$ Fe $_{1.6}$ Se $_{2}$ . In the low-temperature AF state, spin waves can be accurately described by a local moment Heisenberg Hamiltonian. On warming to around the Neel temperature of T_N=500 $K, l o w - e n er g y (E < 30 m e V) p a r ama g n e t i cs p in e x c i t a t i o n s f or m L or e n t z ian - l ik e q u a s i e l a s t i c p e ak sce n t er e d a tt h e A F w a v e v ec t or s a ssoc ia t e d w i t h s p in w a v es, w hi l e hi g h - e n er g y (E > 50 m e V) s p in e x c i t a t i o n s b eco m e h e a v i l y d am p e d . U p o n f u r t h er w a r min g t o ab o v e t h es t r u c t u r a l d i s t or t i o n t e m p er a t u r eo f T_{s} = 524 K, t h ee n t i r e p a r ama g n e t i ce x c i t a t i o n s b eco m eo v er d am p e d . T h eser es u l t ss ug g es tt ha t A F R b$ _{0.8} $F e$ _{1.6} $S e$ _2$ is not a copper-oxide-like Mott insulator, and has less electron correlations compared with metallic iron pnictides and iron chalcogenides.

5 pages, 4 figures

Paramagnetic spin excitations in insulating Rb0.8​Fe1.6​Se2​

Abstract

References in corpus (15)

Paramagnetic spin excitations in insulating Rb $_{0.8}$ Fe $_{1.6}$ Se $_{2}$