DFT and Monte Carlo study of the W(001) surface reconstruction
1 Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauki 46, 252650 Kiev, Ukraine
2 Faculty of Physics, Taras Shevchenko National University, Volodymyrska 64/13, 01612 Kiev, Ukraine
Received: 21 February 2017
Published online: 5 July 2017
The driving force for the W(001) surface reconstruction and electronic structures of pristine and H-covered W(001) surfaces are studied by means of relativistic DFT calculations. The spin-orbit coupling leads to the splitting of the bands. Adsorbed physical monolayer of hydrogen due to forming adsorption bonds stabilizes the (1 × 1) structure of the H/W(001) surface. The performed calculations have not revealed any substantial nesting of Fermi surface, so do not support the Peierls-like charge-density-wave mechanism of the surface reconstruction. The total energy of the (√2 × √2) )R45° W(001) surface structure is found to be lower, by 0.14 eV per atom, than for the (1 × 1 W(001). The dependence of the relative intensity of the characteristic LEED reflection on temperature, obtained with the help of Monte Carlo simulations using the interaction energies estimated from DFT calculations, is in good agreement with available experimental data, thus supporting the concept of the order-disorder type of the transition between the low-temperature ((√2 × √2))R45° and room-temperature (1 × 1) surface structures of W(001).
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2017