Growth Mechanism of Pine-leaf-like Nanostructure from the Backbone of SrCO3Nanorods using LaMer’s Surface Diffusion: Impact of Higher Surface Energy (γ = 38.9 eV/nm2) {111} Plane Stacking Along ⟨110⟩ (γ = 3.4 eV/nm2) by First-Principles Calculations

2017 ◽  
Vol 17 (12) ◽  
pp. 6394-6406 ◽  
Author(s):  
Divya Arumugam ◽  
Mathavan Thangapandian ◽  
Jeshua Linu Joshua Mathavan ◽  
Archana Jayaram ◽  
Murugan Palanichamy ◽  
...  
2013 ◽  
Vol 20 (06) ◽  
pp. 1350054 ◽  
Author(s):  
L. HE ◽  
Y. W. LIU ◽  
W. J. TONG ◽  
J. G. LIN ◽  
X. F. WANG

Surface energies of strained Cu surfaces were studied systematically using first-principles methods. Results showed that the strain-stabilization of Cu surface was anisotropic and strongly related to the strain distribution. This strain-induced approach could be used as an effective way to engineer the surface energies of metals.


2019 ◽  
Vol 479 ◽  
pp. 499-505
Author(s):  
Zhipeng Wang ◽  
Dongchu Chen ◽  
Qihong Fang ◽  
Hong Chen ◽  
Touwen Fan ◽  
...  

2014 ◽  
Vol 778-780 ◽  
pp. 201-205
Author(s):  
Keisuke Sawada ◽  
Jun Ichi Iwata ◽  
Atsushi Oshiyama

We perform the first-principles calculations on the 4H-SiC(0001) surface and clarify the mechanism of the facet formation. We first identify atomic structures of single-, double- and quadribilayer steps and find that the single-bilayer (SB) step has the lowest total energy among these three step structures. Then, we reveal that the nanofacet consisting of SB steps is more energetically stable than the equally spaced SB step and the surface-energy variation caused by the difference of stacking sequences of the bi-atomic layer near the surface is an important factor of the facet formation.


2003 ◽  
Vol 801 ◽  
Author(s):  
Xiliang Nie ◽  
Karl Sohlberg

ABSTRACTTiO2 is well known as a prototype photocatalyst for water dissociation. To understand the mechanism of its photocatalytic water dissociation we performed first-principles calculations. We find that the surface of the catalytically favorable (TiO) termination is very different from the physically favorable (oxygen) termination. The calculated surface energy of the catalytically favorable (TiO) termination is about 10 times larger than that of the physically favorable (oxygen) termination. Analysis of the surface band structure suggests that while O-vacancies are intrinsic active sites for water dissociation into H2 and O2 gas, they are not essential for photocatalytic water dissociation. We also find that carbon impurities decrease the band-gap of TiO2, in agreement with previously reported experimental results. Moreover, we identify the origin of the arcane “double band gap” in carbon doped TiO2. The two onsets seen in the photoabsorption spectrum result from excitations from two of three C p-states within the band gap, not from domains of different composition.


2018 ◽  
Vol 42 (13) ◽  
pp. 10791-10797 ◽  
Author(s):  
Junxiang Xiang ◽  
Bin Xiang ◽  
Xudong Cui

Understanding the correlations between active sites and surface energies of Miller index surfaces is of practical importance to get insights into catalytic efficiency.


2019 ◽  
Vol 25 (2) ◽  
pp. 547-553 ◽  
Author(s):  
Toshiharu Ohnuma

AbstractFirst-principles calculations were performed to determine the Fe on Fe (001) evaporation field and to characterize the surface diffusion of Fe and Cu on Fe (001) and on a step structure under an applied electric field. The evaporation field of Fe on Fe (001) was calculated by the nudged elastic band (NEB) method, using the combination of the effective screening medium and constant electrode potential methods to obtain a condition of constant electric field. The calculated evaporation field of Fe on Fe (001) was 32.4 V/nm, which agrees well with the experimental value. In the surface diffusion of Fe and Cu on Fe (001) and on a step structure, the activation barrier energies were determined by the NEB method with constant applied electric field. It was found that Cu diffuse more easily on the Fe (001) and step structure than Fe under an applied electric field. The activation barrier energy of surface diffusion in the saddle point configuration is small when the distance between Cu and Fe on the surface is larger, and the activation barrier energy becomes smaller when passing through a path far away from the surface due to the effect of the electric field.


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