Stable cation inversion at the MgAl2O4(100) surface.
نویسندگان
چکیده
From an interplay of atom-resolved noncontact atomic force microscopy, surface x-ray diffraction experiments, and density functional theory calculations, we reveal the detailed atomic-scale structure of the (100) surface of an insulating ternary metal oxide, MgAl2O4 (spinel). We surprisingly find that the MgAl2O4(100) surface is terminated by an Al and O-rich structure with a thermodynamically favored amount of Al atoms interchanged with Mg. This finding implies that so-called Mg-Al antisites, which are defects in the bulk of MgAl2O4, become a thermodynamically stable and integral part of the surface.
منابع مشابه
Epitaxial Manganese Oxide Thin Films with Connected Porosity: Topotactic Induction of Crystallographic Pore Alignment
Epitaxial thin films of ZnMn2O4, grown from an aqueous solution on (100) and (111) spinel MgAl2O4 substrates, have been topotactically reduced and leached to produce epitaxial rock salt MnO on the same substrates. The volume change accompanying the conversion of ZnMn2O4 to 2MnO associated with a loss of Zn and O2 manifests as a network of interconnected, 50-100 nm pores. The topotactic nature o...
متن کاملNoncontact atomic force microscopy imaging of atomic structure and cation defects of the polar MgAl2O4 (100) surface: Experiments and first-principles simulations
Morten K. Rasmussen,1 Adam S. Foster,2,3 Filippo F. Canova,2,3 Berit Hinnemann,4 Stig Helveg,4 Kristoffer Meinander,1 Flemming Besenbacher,1 and Jeppe V. Lauritsen1,* 1Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, Denmark 2Department of Physics, Tampere University of Technology, Finland 3Department of Applied Physics, Aalto University School of Science, Finland 4Haldor Top...
متن کاملبررسی آلودگی هوای شهر تهران به روش وارونگی بحرانی هافتر
In issues related to air pollution, the thickness of the boundary layer is known as the depth of the mixed layer because the pollution on the ground surface is mixed in this entire layer through turbulence processes. In most cases, the boundary of the area is clearly visible on big industrial cities. The depth of the mixed layer has an important effect in the concentration of air pollution whic...
متن کاملNon-contact atomic force microscopy study of hydroxyl groups on the spinel MgAl2O4(100) surface.
Atom-resolved non-contact atomic force microscopy (NC-AFM) studies of the magnesium aluminate (MgAl(2)O(4)) surface have revealed that, contrary to expectations, the (100) surface is terminated by an aluminum and oxygen layer. Theoretical studies have suggested that hydrogen plays a strong role in stabilizing this surface through the formation of surface hydroxyl groups, but the previous studie...
متن کاملSolid state synthesis of MgAl2O4 nanomaterials and solar light-induced photocatalytic removal of Malachite Green
Spinel MgAl2O4 nanopowders were synthesized by one-step solid state reactions using Al(NO3)3.9H2O and MgSO4 raw materials at stoichiometric 1 : 2, Mg : Al molar ratio at a constant reaction temperature of 1000 ºC for 8 h (S1), 10 h (S2) and 24 h (S3). The synthesized materials were characterized...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 107 3 شماره
صفحات -
تاریخ انتشار 2011