title: New layered iron sulfide NaFe(1.6)S2: synthesis and characterization.
abstract: Na was intercalated between [Fe2S2] layers for the first time, giving a novel compound NaFe(1.6)S2. This material adopts a CaAl2Si2-type structure with ~20% iron vacancies and represents the first layered compound in a ternary Na-M-X (M = Fe, Co, Ni; X = S, Se) system. First-principles calculations reveal that phonon dynamics is an important factor for it to prefer the CaAl2Si2-type rather than the ThCr2Si2-type structure. It features a magnetic transition at 205 K and is a narrow-band-gap semiconductor.
authors.affiliation: Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , P.O. Box 603, Beijing 100190, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Lai
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Chen
authors.forename: Shifeng
authors.initials: S
authors.lastname: Jin
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhou
authors.forename: Tianping
authors.initials: T
authors.lastname: Ying
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.forename: Shijie
authors.initials: S
authors.lastname: Shen
authors.forename: Wanyan
authors.initials: W
authors.lastname: Wang