Skip to main content
Open Access Publications from the University of California

UC Berkeley

UC Berkeley Previously Published Works bannerUC Berkeley

Two spatially separated phases in semiconducting Rb0.8Fe1.5S2


We report neutron scattering and transport measurements on semiconducting Rb0.8Fe1.5S2, a compound isostructural and isoelectronic to the well-studied A0.8FeySe2(A=K,Rb,Cs,Tl/K) superconducting systems. Both resistivity and dc susceptibility measurements reveal a magnetic phase transition at T=275K. Neutron diffraction studies show that the 275 K transition originates from a phase with rhombic iron vacancy order which exhibits an in-plane stripe antiferromagnetic ordering below 275 K. In addition, the stripe antiferromagnetic phase interdigitates mesoscopically with an ubiquitous phase with 5×5 iron vacancy order. This phase has a magnetic transition at TN=425K and an iron vacancy order-disorder transition at TS=600K. These two different structural phases are closely similar to those observed in the isomorphous Se materials. Based on the close similarities of the in-plane antiferromagnetic structures, moments sizes, and ordering temperatures in semiconducting Rb0.8Fe1.5S2 and K0.81Fe1.58Se2, we argue that the in-plane antiferromagnetic order arises from strong coupling between local moments. Superconductivity, previously observed in the A0.8FeySe2-zSz system, is absent in Rb0.8Fe1.5S2, which has a semiconducting ground state. The implied relationship between stripe and block antiferromagnetism and superconductivity in these materials as well as a strategy for further investigation is discussed in this paper.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View