Superconductivity and magnetism in iron sulfides intercalated by metal hydroxides.

ABSTRACT: Inspired by naturally occurring sulfide minerals, we present a new family of iron-based superconductors. A metastable form of FeS known as the mineral mackinawite forms two-dimensional sheets that can be readily intercalated by various cationic guest species. Under hydrothermal conditions using alkali metal hydroxides, we prepare three different cation and metal hydroxide-intercalated FeS phases including (Li_1-x Fe _x OH)FeS, [(Na_1-x Fe _x )(OH)₂]FeS, and K _x Fe_2-y S₂. Upon successful intercalation of the FeS layer, the superconducting critical temperature T_c of mackinawite is enhanced from 5 K to 8 K for the (Li_1-x Fe _x OH) ^?+ intercalate. Layered heterostructures of [(Na_1-x Fe _x )(OH)₂]FeS resemble the natural mineral tochilinite, which contains an iron square lattice interleaved with a hexagonal hydroxide lattice. Whilst heterostructured [(Na_1-x Fe _x )(OH)₂]FeS displays long-range magnetic ordering near 15 K, K _x Fe_2-y S₂ displays short range antiferromagnetism.

SUBMITTER: Zhou X 

PROVIDER: S-EPMC5436553 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature