Bulletin of the American Physical Society
APS March Meeting 2015
Volume 60, Number 1
Monday–Friday, March 2–6, 2015; San Antonio, Texas
Session J9: Focus Session: van der Waals Bonding in Advanced Materials: Layered Materials |
Hide Abstracts |
Sponsoring Units: DMP Chair: John Dobson, Griffith University Room: 006D |
Tuesday, March 3, 2015 2:30PM - 2:42PM |
J9.00001: Hexagonal Boron Nitride-Water Non-bonded Interaction from First Principles Yanbin Wu, Lucas K. Wagner, Narayana R. Aluru The interaction between water and h-BN is estimated using the M{\o}ller-Plesset perturbation theory of the second order (MP2) and diffusion Monte Carlo (DMC) method. The MP2 and DMC results are verified using coupled cluster treatment with single and double excitations and perturbative triples at the complete basis set limit (CCSD(T)/CBS) using B3N3H6-water as a proxy. The water-h-BN binding energy is estimated as 1.9 $\pm$ 0.2 kcal/mol. Boron/nitride (BN)-water non-bonded interaction parameters are developed based on the MP2 energies. The B/N-water parameters predict the water contact angle on bulk h-BN surface that is in good agreement with experimental measurements. [Preview Abstract] |
Tuesday, March 3, 2015 2:42PM - 2:54PM |
J9.00002: Role of weak interactions in phase transitions of layered transition metal dichalcogenides: An ab initio study Niladri Sengupta, Adrienn Ruzsinszky, John P. Perdew Phase transitions of layered materials are not often clearly explained and captured by the GGA level density functional calculations. Weak interactions might play an important role in these phase transitions. Now GGA can not describe well weak interactions. So we intend to use several new meta GGAs (TPSS, RevTPSS, MS family etc.), many body VDW corrected meta GGAs and RPA to study phase transitions of layered transition metal dichalcogenides (ME$_{2}$ ; M $=$ Ti, V, Cr, Ta, Mo, W ; E $=$ Se, S, Te) and investigate the role of weak interactions in those cases. [Preview Abstract] |
Tuesday, March 3, 2015 2:54PM - 3:06PM |
J9.00003: Dispersion Forces of Adatoms on Deformed Graphene Valeri Kotov van der Waals (vdW) forces are especially important near atomically-thin materials, such as graphene, boron nitride (h-BN) and transition metal dichalcogenides (e.g. MoSe2), which form the building blocks of the so-called van der Waals heterostructures. These systems can also exhibit strong deformations in their structure due to stress, either applied externally, or induced by the presence of a substrate. A problem of fundamental and technological importance is how the vdW forces, which reflect Coulomb interactions and polarization effects, depend on electronic and mechanical material properties. I will show that strain fields can greatly enhance the vdW interactions of neutral adatoms near graphene and structurally similar surfaces, thus substantially affecting adsorption properties and altering the dissipative dynamics associated with atomic motion. For the case of two strained graphene sheets similar enhancement was predicted by A. Sharma et.al., PRB 89, 235425 (2014). I will consider several aspects of the adatom-graphene problem: (1) Variation of the vdW force as a function of uniaxial and more general strain fields, (2) Dependence on electron-electron interactions, including renormalization effects near the Dirac point, (3) Implications for dissipative atom dynamics. [Preview Abstract] |
Tuesday, March 3, 2015 3:06PM - 3:42PM |
J9.00004: RPA and beyond-RPA total energy methods for strongly and weakly bonded materials Invited Speaker: Kristian Thygesen The random phase approximation (RPA) is attracting renewed interest as a universal and accurate method for first-principles total energy calculations. The RPA naturally accounts for long-range dispersive forces making the RPA superior to density and hybrid functionals in systems dominated by weak van der Waals or mixed covalent-dispersive interactions. We have applied the RPA to calculate the potential energy surfaces of graphene on various metal surfaces. For some of the metals, the RPA binding energy curve shows two distinct minima which arise from a delicate balance between covalent and dispersive forces that are not captured by standard semilocal or van der Waals density functionals [1]. We benchmark the RPA by calculating cohesive energies of graphite and a range of covalently bonded solids and molecules as well as the dissociation curves of H2 and H2$+$. These results show that the RPA with orbitals from the local density approximation suffers from delocalization errors and systematically underestimates covalent bond energies yielding similar or lower accuracy than the Perdew-Burke-Ernzerhof (PBE) functional for molecules and solids [1]. Inclusion of an adiabatic xc-kernel defined through a renormalization of the LDA kernel is found to significantly improve the RPA description of short range correlations yielding essentially exact results for the homogeneous electron gas [2]. By generalizing this renormalized LDA xc-kernel to inhomogeneous systems we find a fourfold improvement of RPA binding energies in both molecules and solids. We also consider examples of barrier heights in chemical reactions, molecular adsorption, and graphene interacting with metal surfaces, which are three examples where the RPA has been successful. In these cases, the renormalized kernel provides results that are of equal quality or even slightly better than the RPA, with a similar computational cost [3]. \\[4pt] [1] T. Olsen and K. S. Thygesen, Phys. Rev. B 87, 075111 (2013)\\[0pt] [2] T. Olsen and K. S. Thygesen, Phys. Rev. B 88, 115131 (2013)\\[0pt] [3] T. Olsen and K. S. Thygesen, Phys. Rev. Lett. 112, 203001 (2014) [Preview Abstract] |
Tuesday, March 3, 2015 3:42PM - 3:54PM |
J9.00005: The Quantum Monte Carlo studies of Van der Waals interaction in bilayer systems Ching-Ming Wei, Cheng-Rong Hsing, Ching Cheng, Chun-Ming Chang Van der Waals (vdW) interaction is one of the most fundamental physical quantities resulted from the quantum fluctuation of charges. However, it remains a challenge to account for this interaction quantitatively in both theory and experiment. For example, vdW interaction is one of the physical properties that the LDA and GGA of Density Functional Theory (DFT) fail to describe correctly. In recent years, there have been many proposals of DFT-vdW to overcome this deficiency. However, discrepancies in binding energy among these DFT-vdW results are usually apparent. In this talk, we present the Quantum Monte Carlo (QMC) and DFT studies of various bilayer systems: BN/BN [New. J. Phys. 16, 113015 (2014)], Silicene/Graphene, Silicene/BN and MoS2/Graphene. The calculations show large discrepancies among various DFT functionals. The QMC calculated binding energy was found to be larger than that obtained by the LDA calculation and smaller than those using DFT-vdW correction. Moreover, the QMC calculated interlayer interaction was found to have a longer-range behavior than all the available DFT schemes. The outcome of the present QMC study would provide a benchmark for future generation of various DFT XC functionals and guidance for prospective experiments. [Preview Abstract] |
Tuesday, March 3, 2015 3:54PM - 4:06PM |
J9.00006: Ni(111)-graphene interface: the importance of screened van der Waals interactions Pier Luigi Silvestrelli, Alberto Ambrosetti Due to the direct applicability of Ni(111) surfaces in high-quality graphene production, the Ni(111)-graphene interface has recently been the object of extensive experimental and theoretical investigations. Achieving an accurate and efficient theoretical description of the Ni(111)-graphene interaction, however, still represents a major theoretical challenge, due to the complex interplay between van der Waals (vdW) and hybridization effects. Here we apply the DFT/vdW-WF2s method [1], augmenting semi-local Density Functional Theory through the inclusion of screened vdW interactions. Interestingly, we show that a reliable description of the vdW energy in Ni(111)-graphene requires an appropriate modeling of the metal-screening, which should not only account for the p- and s-like \textit{quasi-free} electrons, but should further include the effect of the more \textit{localized} d-like states. Good agreement is found with experiment and highly accurate theoretical predictions. Moreover, being the DFT/vdW-WF2s method based on Maximally Localized Wannier Functions, it permits an intuitive understanding of the complex physics underlying transition metals-graphene interactions.\\[4pt] [1] P. L. Silvestrelli and A. Ambrosetti, Phys. Rev. B 87, 075401 (2013). [Preview Abstract] |
Tuesday, March 3, 2015 4:06PM - 4:18PM |
J9.00007: ZnO-Graphene Interfacial Binding Strength: Dependence on Surface Orientation Haiying He, Kelsey Larson, Adam Clark, Allyse Appel, Stan Zygmunt There is an increasing interest of hybridized materials with impacts such as improving structural integrity of known and commonly used materials. Recent experiments have suggested that the adhesion of zinc oxide (ZnO) nanowires with carbon fibers can significantly improve interfacial shear strength of fiber reinforced composites. We have carried out a systematic study of the interaction between ZnO and graphene based on density functional theory, with a focus on the effect of the surface orientation and termination of ZnO. It is found that the calculated interfacial binding strength strongly depends upon the surface orientation and termination of ZnO. Only slight variation in binding energy is observed for different binding sites and Zn/O atoms with different coordination numbers. Comparison of results using a variety of exchange-correlation functionals with different forms of dispersion corrections will be presented. [Preview Abstract] |
Tuesday, March 3, 2015 4:18PM - 4:30PM |
J9.00008: Structural and Electronic Properties of BC 3 with Van der Waals Density Functional Theory Burak Ozdemir, Veronica Barone Layered materials have attracted a lot of attention recently due to their unique properties that can be optimized for technological applications such as energy storage and transparent conductors. Among these materials, a graphite-like BC3 (g-BC3) structure has been recently under investigation as it provides a similar morphology than graphite but with a large concentration of electron deficient B atoms. Despite the recent experimental and theoretical works, the morphology of this materials is still not well undertsood. In this work, stable stacking configurations of g-BC3 have been determined using different exchange-correlation functionals that include dispersion corrections. We identify the most stable structures and characterize their electronic properties. [Preview Abstract] |
Tuesday, March 3, 2015 4:30PM - 4:42PM |
J9.00009: Measurement of the long range van der Waals force in graphene Jun Xu, Alexandr Banishev, Umar Mohideen The gradient of the long range van der Waals force between a Si-SiO2 -graphene substrate and an Au-coated sphere is measured by means of a dynamic atomic force microscope operated in the frequency shift technique. It is shown that the presence of graphene leads to up to a 9{\%} increase in the force gradient at the shortest separation considered. The experimental results are compared to a theory of the long range thermal van der Waals interaction for multilayered test bodies coated with a graphene sheet and found to be in good agreement. References: .[1] A.A. Banishev, H. Wen, J. Xu, R.K. Kawakami, G.L. Klimchitskaya, V.M. Mostepanenko, U. Mohideen, Measuring the Casimir force gradient from graphene on a SiO2 substrate, Phys. Rev. B, 87 (2013) 5. [2] G.L. Klimchitskaya, U. Mohideen, V.M. Mostepanenko, Theory of the Casimir interaction from graphene-coated substrates using the polarization tensor and comparison with experiment, Phys. Rev. B, 89 (2014) 8. [Preview Abstract] |
Tuesday, March 3, 2015 4:42PM - 4:54PM |
J9.00010: Van der Waals screening by single-layer graphene and molybdenum disulfide Stanislav Tsoi, Pratibha Dev, Adam Friedman, Jeremy Robinson, Rory Stine, Thomas Reinecke, Paul Sheehan We used a sharp tip of an atomic force microscope to experimentally measure van der Waals forces of a silicon oxide substrate with adhered graphene, prepared by micromechanical cleavage. Data obtained in the range of separations from 3 to 20 nm indicated that single-, double-, and triple-layer graphenes screened the van der Waals forces of the substrate. The van der Waals force from graphene determined per layer was found to decrease with the number of layers. In addition, increased hole doping of graphene enhanced the force. The screening was lifted in the single-layer graphene upon its fluorination, which rendered it electrically insulating. Finally, we also demonstrated strong screening of the van der Waals forces of the silicon oxide substrate by single- and double-layer molybdenum disulfide. Analysis of the experimental results was aided by density functional theory calculations. [Preview Abstract] |
Tuesday, March 3, 2015 4:54PM - 5:06PM |
J9.00011: Interlayer Binding of Bilayer $\alpha $-graphyne : Quantum Monte Carlo Study Yongkyung Kwon, Hyeondeok Shin, Hoonkyung Lee, Jeongnim Kim Graphynes have recently received considerable attention because of their intriguing potential as new Dirac materials. Recent DFT calculations of Leenaerts \textit{et al.} [1] predicted two stable stacking modes of bilayer $\alpha $-graphyne; while a AB-stacked configuration was found to possess a gapless parabolic band structure, the other stable mode of Ab-stacked graphyne exhibits a double Dirac cone spectrum. On the other hand, more accurate DFT calculations predicted different ground-state configurations for bilayer $\alpha $-graphyne, depending on the van der Waals (vdW)-corrected exchange-correlation functional used.~In order to determine the most stable configuration of bilayer $\alpha $-graphyne along with accurate computation of its interlayer binding energy, we here employ quantum Monte Carlo method which allows accurate description of the vdW interaction between two graphyne layers.~The QMC results for the interlayer binding energies have revealed that the Ab-stacking mode is slightly favored than the AB mode but the binding energy difference is very small, only about 0.3 meV/atom. It is also found that the DFT results with vdW-DF2, based on the non-local vdW functional proposed by Lee \textit{et al}. [2], are in good agreement with the QMC results. This leads us to conclude that within the DFT formalism the interlayer binding of the graphyne structures is best described by the vdW-DF2 functional. [1] O. Leenaerts \textit{et al}., Appl. Phys. Lett. \textbf{103}, 013105 (2013). [2] K. Lee \textit{et al}., Phys. Rev. B \textbf{82}, 081101R (2010). [Preview Abstract] |
Tuesday, March 3, 2015 5:06PM - 5:18PM |
J9.00012: Adapting DFT C6-corrections for modeling graphene on metal surfaces Peter Schultz, Michael Foster Modeling graphene on metals accurately presents a challenge for first principles due to difficulties modeling non-local electron correlation. An effective model must resolve small van der Waals (vdW) binding of graphene to the surface from the large cohesive energy in the metal and chemical bond energies in the graphene. Conventional density functional theory (DFT) such as GGA/PBE fails to describe vdW effects accurately. More sophisticated non-local vdW functionals, still in their infancy, produce inconsistent results, and there is a shortage of experimental data to assess which of these is more reliable. Moreover, computational expense limits their general application. We adapt DFT plus C6-corrected methods in concert with non-local vdW functionals to study graphene on Cu(111), Ni(111), and Ir(111). The known strengths of vdW-functionals and limited experimental data are used to constrain the definition of the C6-corrections (which in turn provides guidance as to which vdW-enhanced functionals are most suitable for accurate simulations of graphene adsorption on metals). The less expensive DFT+C6 and vdW-DFT are shown to give consistent results, and agree with known experimental data for these three metal surfaces. [Preview Abstract] |
(Author Not Attending)
|
J9.00013: Influence of Graphene Coating on the Adsorption and Tribology of Xeon Au(111) Substrate Yanning Zhang, V. Bortolani, G. Mistura The adsorption and tribological properties of graphene have received increasing attention for the further development of graphene-based coatings in applications. In thiswork, we performed first principles calculations with the inclusion of the nonlocal van der Waals correction to study the effect of graphene coating on the adsorption geometries, sliding frictions and electronic properties of Xe monolayer on the Au(111) substrate. Thecalculated activation energies indicate that Xe becomes movable on pure Au(111) surface at a temperature of around 30 K, whereas its motion can be activated only at a high temperature of $\sim$ 50 K on graphene and on graphene-coated Au(111) substrates, in good agreement with recent experimental measurements by quartz crystal microbalance technique. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700