Observation of the V2O5(001) surface using ambient atomic force microscopy

Ab Initio Density Functional Theory Studies of Hydrogen Adsorption at the V2O5(010) Surface

“…Further, the study yields a surface geometry of V 2 O 5 (010) which is very close to that defined by ideal bulk termination. This suggests the absence of major relaxation and reconstruction at the clean single crystal V 2 O 5 (010) surface in good agreement with recent experimental results [31,32]. The present ab initio FP-LAPW calculations on V 2 O 5 (010) single layer slabs based on the repeated slab geometry approach and ab initio studies on size converged V 2 O 5 (010) surface clusters using the deMon code arrive at the same qualitative results concerning H adsorption.…”

“…Further, it suggests strongly that the geometry and electronic structure of the V 2 O 5 (010) surface (terminated by a single layer slab) can be represented quite well by that of an isolated V 2 O 5 (010) single layer slab. Hence, the present theoretical results are consistent with the absence of major reconstruction at the clean single crystal V 2 O 5 (010) surface which is observed in the experiment [31,32].…”

Understanding the atomic force microscopy image of the V2O5 and Li0.03V2O5(001) surface using ab initio calculations

“…Numerical approximations are introduced in the evaluation of the Coulomb and exchange series for infinite systems. In the CRYSTAL code, the accuracy is controlled by a set of ''cutoff'' tolerances (see [16] for details); the values we have chosen (8,7,8,8,16) reduce the effect of numerical inaccuracies to a minimum. The contribution of electron correlation to the total energy, neglected in pure Hartree-Fock approximation, was evaluated by a posterior scheme based on correlation-only density-functional formulas [20].…”

“…Such total electrondensity plots, calculated using the extended Hückel tightbinding (EHTB) electronic band-structure method [6], have been necessary to explain the observed STM and AFM images of a large number of organic conducting salts, transition-metal chalcogenides and transition-metal halides [4,5]. In ambient conditions, our previous observations of V 2 O 5 (0 0 1) single crystal surface [7,8] give result which is some different from the ideal surface as observed by Smith et al [9]; however, it is important to notice that sample used by Smith et al was doped with Na and it is well known that some alkali atoms remain in the first layers of the bulk [10] and so surface behaviours can be modified. Accordingly, we were interested by the investigation of the clean and lithiated V 2 O 5 (0 0 1) single crystal surface in order to examine the influence of the simplest alkali atoms (here the lithium) on the catalytic properties of the (0 0 1) plane.…”

Electronic Structure of Unsaturated V2O5(001) and (100) Surfaces: Ab Initio Density Functional Theory Studies

“…The large interest in the (010) surface properties can be explained by the layered structure of V 2 O 5 bulk where atomic layers along the (010) direction are weakly bound and generate cleavage planes seen by AFM (Atomic Force Microscopy), as well as STM (Scanning Tunneling Microscopy) experiments [41,42]. Also MD (Molecular Dynamic) simulations (based on electrostatic interactions) of the thermal stability of the V 2 O 5 structure have indicated the (010) netplane as the most stable among the three low-index surfaces of V 2 O 5 [43].…”