Two-Dimensional Iron Tungstate: A Ternary Oxide Layer With Honeycomb Geometry.
The exceptional physical properties of graphene have sparked tremendous interests toward two-dimensional (2D) materials with honeycomb structure. We report here the successful fabrication of 2D iron tungstate (FeWOx) layers with honeycomb geometry on a Pt(111) surface, using the solid-state reaction of (WO3)3clusters with a FeO(111) monolayer on Pt(111). The formation process and the atomic structure of two commensurate FeWOxphases, with (2 × 2) and (6 × 6) periodicities, have been characterized experimentally by combination of scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption (TPD) and understood theoretically by density functional theory (DFT) modeling. The thermodynamically most stable (2 × 2) phase has a formal FeWO3stoichiometry and corresponds to a buckled Fe2+/W4+layer arranged in a honeycomb lattice, terminated by oxygen atoms in Fe-W bridging positions. This 2D FeWO3layer has a novel structure and stoichiometry and has no analogues to known bulk iron tungstate phases. It is theoretically predicted to exhibit a ferromagnetic electronic ground state with a Curie temperature of 95 K, as opposed to the antiferromagnetic behavior of bulk FeWO4materials.
Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz , A-8010 Graz, Austria.
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Pomp
Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz , A-8010 Graz, Austria.
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Kuhness
CNR-ICCOM and IPCF, Consiglio Nazionale delle Ricerche, I-56124 Pisa, Italy.
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Barcaro
CNR-ICCOM and IPCF, Consiglio Nazionale delle Ricerche, I-56124 Pisa, Italy.
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Sementa
Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz, A-8010 Graz, Austria; CNR-ICCOM and IPCF, Consiglio Nazionale delle Ricerche, I-56124 Pisa, Italy.
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Mankad
CNR-ICCOM and IPCF, Consiglio Nazionale delle Ricerche, I-56124 Pisa, Italy.
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Fortunelli
Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz , A-8010 Graz, Austria.
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Sterrer
Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz , A-8010 Graz, Austria.
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Netzer
Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz , A-8010 Graz, Austria.
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