Synthesis of tetragonal mackinawite-type FeS nanosheets by solvothermal crystallization

• Published in: Journal of solid state chemistry Vol. 196; pp. 17 - 20
• Main Authors: Sines, Ian T., Vaughn II, Dimitri D., Misra, Rajiv, Popczun, Eric J., Schaak, Raymond E.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.12.2012; Elsevier
• Subjects: Chalcogenides; CHEMICAL PREPARATION; Chemical synthesis methods; Condensed matter: structure, mechanical and thermal properties; COPRECIPITATION; Cross-disciplinary physics: materials science; rheology; Crystal structure; CRYSTALLIZATION; Ethylene glycol; Exact sciences and technology; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Iron; Iron sulfide; IRON SULFIDES; Lattice parameters; Mackinawite; Materials science; Metastable phase; Methods of nanofabrication; MONOCRYSTALS; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; NANOSCIENCE AND NANOTECHNOLOGY; Nanosheets; Nanostructure; NANOSTRUCTURES; Physics; Solution synthesis; Structure of solids and liquids; crystallography; SUPERCONDUCTIVITY; Nanosheets; Nanostructures; Iron sulfide; Solution synthesis; Mackinawite; Metastable phase; Lead oxide; Ethylene glycol; Nanoplate; Nanosheet; Metastable phases; Metastable states; Crystallization; Superconductivity; Ferromagnetic materials; Iron; Lattice parameters; Precursor; Faceting; Thickness; Sulfur; Coprecipitation; Crystal structure
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2012.07.056

Mackinawite, a metastable 1:1 compound of iron and sulfur that adopts an anti-PbO-type structure, is of interest because of its relationship to known iron chalcogenide superconductors, as well as its biogeochemical relevance. Colloidal nanosheets of mackinawite-type FeS were synthesized by first generating an amorphous Fe–S precursor via the aqueous room-temperature co-precipitation of Fe2+ and S2−, then solvothermally crystallizing it in ethylene glycol at 200°C in an autoclave. The product is highly crystalline, with lattice constants of a=3.674(3)Å and c=5.0354(3)Å. The nanosheets, with their surface normal oriented along the [001] direction, are irregularly faceted with edge lengths that range from 100nm to over 1μm and average thicknesses of approx. 30nm. The samples showed a ferromagnetic background signal with no evidence of superconductivity. Single-crystal colloidal nanosheets of mackinawite-type FeS were synthesized by the solvothermal crystallization of an amorphous Fe–S precursor. [Display omitted] ► Aqueous co-precipitation yields an amorphous Fe–S precursor. ► The amorphous precursor solvothermally crystallizes to form metastable mackinawite. ► Mackinawite-type FeS forms as single crystal colloidal nanosheets. ► Samples are ferromagnetic with no evidence of superconductivity.