Noncontact atomic force microscopy study of the spinel MgAl2O4(111) surface

作者：Rasmussen Morten K; Meinander Kristoffer; Besenbacher Flemming; Lauritsen Jeppe V^*

来源：Beilstein Journal of Nanotechnology, 2012, 3: 192-197.

DOI：10.3762/bjnano.3.21

• aluminium oxide
• metal oxide surfaces
• noncontact atomic force microscopy (NC-AFM)
• polar surfaces
• reconstructions
• spinel

Based on high-resolution noncontact atomic force microscopy (NC-AFM) experiments we reveal a detailed structural model of the polar (111) surface of the insulating ternary metal oxide, MgAl2O4 (spinel). NC-AFM images reveal a 6 root 3x6 root 3R30 degrees superstructure on the surface consisting of patches with the original oxygen-terminated MgAl2O4(111) surface interrupted by oxygen-deficient areas. These observations are in accordance with previous theoretical studies, which predict that the polarity of the surface can be compensated by removal of a certain fraction of oxygen atoms. However, instead of isolated O vacancies, it is observed that O is removed in a distinct pattern of line vacancies reflected by the underlying lattice structure. Consequently, by the creation of triangular patches in a 6 root 3x6 root 3R30 degrees superstructure, the polar-stabilization requirements are met.

• 出版日期2012-3-6