(CaO)(FeSe): A layered wide-gap oxychalcogenide semiconductor

Journal Article · Mon Jul 20 00:00:00 EDT 2015 · Chemistry of Materials

DOI:https://doi.org/10.1021/acs.chemmater.5b02164· OSTI ID:1354773

Han, Fei ^[1]; Wang, Di ^[2]; Malliakas, Christos D. ^[3]; Sturza, Mihai ^[1]; Chung, Duck Young ^[1]; Wan, Xiangang ^[2]; Kanatzidis, Mercouri G. ^[3]

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1. Argonne National Lab. (ANL), Argonne, IL (United States)
2. Nanjing Univ., Nanjing (China)
3. Argonne National Lab. (ANL), Argonne, IL (United States); Northwestern Univ., Evanston, IL (United States)

A new iron-oxychalcogenide (CaO)(FeSe) was obtained which crystallizes in the orthorhombic space group Pnma (No. 62) with a = 5.9175(12) Å, b = 3.8797(8) Å, c = 13.170(3) Å. The unique structure of (CaO)(FeSe) is built up of a quasi-two-dimensional network of corrugated infinite layers of corner-shared FeSe₂O₂ tetrahedra that extend in the ab-plane. The FeSe₂O₂ layers stack along the c-axis with Ca²⁺ cations sandwiched between the layers. Optical spectroscopy and resistivity measurements reveal semiconducting behavior with an indirect optical band gap of around 1.8 eV and an activation energy of 0.19(1) eV. Furthermore, electronic band structure calculations at the density function level predict a magnetic configuration as ground state and confirm the presence of an indirect wide gap in (CaO)(FeSe).

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1354773
• Journal Information: Chemistry of Materials, Vol. 27, Issue 16; ISSN 0897-4756
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY