Krypton clusters adsorbed on graphite: A low-temperature commensurate-incommensurate transition

Houlrik, Jens M.; Landau, D. P.; Jensen, Svend J. Knak

doi:10.1103/physreve.50.2007

Cited by 11 publications

(6 citation statements)

References 34 publications

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“…Thus the first order transition along the adsorption branch is due to (1) a liquid-solid transition in the contact layer and (2) a compressed gas to solid transition in the inner layer. It should be noted that the temperature 87K is above the bulk triple point 83.78K and the RDD shows that the 2D solid is square packed, as observed by other researchers [17,31,[41][42][43].…”

Section: Adsorption Of Argon In An Infinite Pore At 87ksupporting

confidence: 76%

On the adsorbate restructuring induced hysteresis of simple gas adsorption in slit micropores

Diao

Fan

et al. 2016

Chemical Engineering Journal

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Simulations of adsorption isotherms for simple gases in homogeneous slit pores with two open ends often show hysteresis, between condensation and evaporation branches. The hysteresis may result either, from the difference in the curvature of the interface separating the adsorbed and gas phases, or from molecular restructuring when the adsorbate is densely packed. The order-disorder transition that occurs in the second case, has also been observed experimentally for adsorption on a graphite surface, and is supported by molecular simulation [1,2]. In this paper we report a comprehensive set of GCMC simulations designed to explore the effects of pore size and temperature on the hysteresis loop induced by adsorbate restructuring. We report isotherms, isosteric heats, and microscopic analyses of the local density distribution, and the 2D and 3D radial density distributions. Local compressibilities reinforce the supposition that adsorbate restructuring is the origin of the ordering hysteresis.

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Section: Adsorption Of Argon In An Infinite Pore At 87ksupporting

confidence: 76%

On the adsorbate restructuring induced hysteresis of simple gas adsorption in slit micropores

Diao

Fan

et al. 2016

Chemical Engineering Journal

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“…The simulated isotherms at 77K are shown in Figure 1. The structureless model cannot account for the incommensurate to commensurate transitions that have received much attention in the past, especially for very low temperature systems [9,13,14,20] . However, the figure shows that the structureless surface model captures all the major features of interest, including the 2D-transition and the sub-steps.…”

Section: Krypton Adsorption On Graphite Surface At 77 Kmentioning

confidence: 99%

On the 2D-transition, hysteresis and thermodynamic equilibrium of Kr adsorption on a graphite surface

Diao

Fan

et al. 2015

Journal of Colloid and Interface Science

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The adsorption and desorption of Kr on graphite at temperatures in the range 60 K to 88 K, was systematically investigated using a combination of several simulation techniques including: grand canonical Monte Carlo (GCMC), canonical kinetic-Monte Carlo (C-kMC) and the Mid-Density scheme (MDS). Particular emphasis was placed on the gas-solid, gas-liquid and liquid-solid 2D phase transitions. For temperatures below the bulk triple point, the transition from a 2D-liquid-like monolayer to a 2D-solid-like state is manifested as a sub-step in the isotherm. A further increase in the chemical potential leads to another rearrangement of the 2D-solidlike state from a disordered structure to an ordered structure that is signalled by (1) another sub-step in the monolayer region and (2) a spike in the plot of the isosteric heat versus density at loadings close to the dense monolayer coverage concentration. Whenever a 2D transition occurs in a grand canonical isotherm it is always associated with a hysteresis, a feature that is not widely recognized in the literature. We studied in details this hysteresis with the analysis of the canonical isotherm, obtained with C-kMC, which exhibits a van der Waals (vdW) type loop with a vertical segment in the middle. We complemented the hysteresis loop and the vdW curve with the analysis of the equilibrium transition obtained with the MDS, and found that the equilibrium transition coincides exactly with the vertical segment of the C-kMC isotherm, indicating the coexistence of two phases at equilibrium. We also analysed adsorption at higher layers and found that the 2D-coexistence is also observed, provided that the temperature is well below the triple point. Finally the 2D-critical temperatures were obtained for the first three layers and they are in good agreement with the experimental data in the literature.

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“…In particular, it has been demonstrated that already at submonolayer coverages and at sufficiently low temperatures, the addition of argon into krypton film triggers the C-IC transition, and leads to the formation of finite clusters in which small commensurate domains consisting of pure krypton are separated by heavy walls built of argon and krypton [51]. The C-IC transition in one-component finite clusters of Lennard-Jones atoms adsorbed on graphite has also been studied by Houlrik et al [37]. They have used Monte Carlo method to study the effects of the corrugation potential on the structure of finite systems and have shown that for a given amplitude of the corrugation potential the presence of free surfaces enhanced the stability of the C structure.…”

Section: Introductionmentioning

confidence: 96%

“…The commensurate-incommensurate (C-IC) transitions in adsorbed films have been experimentally observed in a variety of systems [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and studied by theoretical methods [16][17][18][19][20][21][22][23][24][25][26][27] and computer simulations [28][29][30][31][32][33][34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

The mechanism of domain-wall structure formation in Ar-Kr submonolayer films on graphite

Patrykiejew¹,

Sokołowski²

2014

Condens. Matter Phys.

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Using Monte Carlo simulation method in the canonical ensemble, we have studied the commensurateincommensurate transition in two-dimensional finite mixed clusters of Ar and Kr adsorbed on graphite basal plane at low temperatures. It has been demonstrated that the transition occurs when the argon concentration exceeds the value needed to cover the peripheries of the cluster. The incommensurate phase exhibits a similar domain-wall structure as observed in pure krypton films at the densities exceeding the density of a perfect ( 3 × 3)R30 • commensurate phase, but the size of commensurate domains does not change much with the cluster size. When the argon concentration increases, the composition of domain walls changes while the commensurate domains are made of pure krypton. We have constructed a simple one-dimensional FrenkelKontorova-like model that yields the results being in a good qualitative agreement with the Monte Carlo results obtained for two-dimensional systems.

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Krypton clusters adsorbed on graphite: A low-temperature commensurate-incommensurate transition

Cited by 11 publications

References 34 publications

On the adsorbate restructuring induced hysteresis of simple gas adsorption in slit micropores

On the adsorbate restructuring induced hysteresis of simple gas adsorption in slit micropores

On the 2D-transition, hysteresis and thermodynamic equilibrium of Kr adsorption on a graphite surface

The mechanism of domain-wall structure formation in Ar-Kr submonolayer films on graphite

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