Adsorption and diffusion of a Cl adatom on the GaAs(001)-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>c</mml:mi><mml:mo>(</mml:mo><mml:mn>8</mml:mn><mml:mn /><mml:mo>×</mml:mo><mml:mn>2</mml:mn><mml:mo>)</mml:mo></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>ζ</mml:mi></mml:math>surface

This is part II in a series of two papers that introduce a general expression for the tracer diffusivity in complex, periodic energy landscapes with M distinct hop rates in one-, two-, and three-dimensional diluted systems (low coverage, single-tracer limit). While Part I [Gosálvez et al., Phys. Rev. B 93, 075429 (2016)] focuses on the analysis of diffusion in systems where the end sites of the hops are located symmetrically with respect to the hop origins (symmetric hops), as encountered in many ideal surfaces and bulk materials, this report (Part II) presents a more general approach to determining the tracer diffusivity in systems where the end sites can be located asymmetrically with respect to the hop origins (asymmetric hops), as observed in reconstructed and/or chemically modified surfaces and/or bulk materials. The obtained diffusivity formulas for numerous systems are validated against kinetic Monte Carlo simulations and previously reported analytical expressions based on the continuous-time random walk (CTRW) method. The proposed method corrects some of the CTRW formulas and provides new expressions for difficult cases that have not been solved earlier. This demonstrates the ability of the proposed formalism to describe tracer diffusion.

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“…(c) Cl on the GaAs(001)-c(8×2) ζ surface, based on Ref. [8]. (d) A general 2D rectangular lattice with two adsorption sites.…”

Section: A Asymmetric Hopsmentioning

confidence: 99%

Low-coverage surface diffusion in complex periodic energy landscapes. II. Analytical solution for systems with asymmetric hops

et al. 2016

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“…This is consistent with an attractive interaction between pairs of HfO 2 adsorbates. These are "binding energies" as defined by Lee et al 42 because the energy of the adsorbate complex is compared to that of the clean surface and the gas phase adsorbate instead of a true bulk reference state for the adsorbate. Both top down and side view ball-and-stick diagrams for the four sites simulated are presented in Table I, where the side view shows the entire slab thickness including the pseudohydrogen termination layer.…”

Section: B High-oxide Adsorption On Inas"0 0 1…-"4 ã 2…mentioning

confidence: 99%

Theoretical analysis of initial adsorption of high-κ metal oxides on InxGa1−xAs( 1)-(4×2) surfaces

Bishop

Clemens

Chagarov

et al. 2010

The Journal of Chemical Physics

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Ordered, low coverage to monolayer, high-κ oxide adsorption on group III rich InAs(0 0 1)-(4×2) and In(0.53)Ga(0.47)As(0 0 1)-(4×2) was modeled via density functional theory (DFT). Initial adsorption of HfO(2) and ZrO(2) was found to remove dangling bonds on the clean surface. At full monolayer coverage, the oxide-semiconductor bonds restore the substrate surface atoms to a more bulklike bonding structure via covalent bonding, with the potential for an unpinned interface. DFT models of ordered HfO(2)/In(0.53)Ga(0.47)As(0 0 1)-(4×2) show it fully unpins the Fermi level.

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