CARBONHAGEN 2021 - Questions during STEPHAN ROCHEs talk (LEAVE YOUR NAME) by https://padlet.com/peterboggild/pgp4ifp0rrppv6qf Ask questions during the talk, and answer/comments others questions en-us 2021-02-11 18:08:29 UTC 2025-12-21 14:11:45 UTC hello@padlet.com https://padlet-uploads.storage.googleapis.com/969593974/0778ea78e72ae8597bb2e865eca6bc30/cbh2021.jpg Peter B: can you also simulate annealing - in some way thermally induced relaxation of lattice defects - using your MD code? peterboggild https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203614610 2021-02-15 13:20:46 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203614610 Peter B: what is the typical reflection probability for grain boundaries in your calculations? peterboggild https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203639687 2021-02-15 13:29:24 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203639687 Sam D. : When comparing the maximum theoretical mobility of PG (300.000) to the experimental one (~3.000), there is one to two order of magnitude discrepancy (with some of them). How do you explain the difference ? Especially taking in account that defects would have a similar effect than GBs (right ?), so it does not seem to be a likely explanation. By looking at your slides, the effect of heavy absorption (200%) does not seem to explain such discrepancy. Thanks for you answer and the excellent talk. https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203647627 2021-02-15 13:31:58 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203647627 Luna Z: How does roadmaps (for example, International Roadmap for Devices and Systems) help advancing a specific field? And how do researchers choose which roadmap as a guidance for own research?Thank you https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203661982 2021-02-15 13:37:02 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203661982 Krishna: You mentioned the grain-boundary resistivity is independent of temperature (~0 - 300K). Is it means the strain does not affect this grain-boundary resistivity? https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203667609 2021-02-15 13:38:46 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203667609 https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203677208 Hi Stephan: Graphene films are polycrystalline. What is the minimal size of the single domain graphene that industry needs? (from Marc Monthioux)]]> 2021-02-15 13:41:36 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203677208 Krishna: Would you mind brief what makes the Gr-hBN boundary cause emission of photons (PL) ? https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203683708

]]> 2021-02-15 13:43:31 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203683708 Hi Stephan: Are there are other strategies that could be explored to reduce grain boundaries? For example in other materials such as Si, seed crystals can be used to initiate monocrystal growth? Or maybe some sort of simultaneous growth/etching similar to Ostwald ripening? (from Chris Ewels) https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203685900 2021-02-15 13:44:20 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203685900 Singh: Have one tried a Fractional Quantum Hall Effect in Polycrystalline Graphene?? Or is it very difficult?? Does grain boundary has to do anything with interactions in the graphene systems.. thanks.. https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203692407 2021-02-15 13:46:19 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203692407 Sam D. : if Ls depends only on the spin-orbit coupling (Rashba like), have you investigated how the molecules absorbed at the GBs play a role similar to the substrate ? even though SOC scales as Z^4 when comparing the metal substrate and those molecules (C,O,...) https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203693357 2021-02-15 13:46:37 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203693357 Krishna: Is there any interesting facts available with TMDC grain boundaries with BN as well ? https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203697664 2021-02-15 13:48:11 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203697664 Martin: lhk5200 https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203700162 How does the breaking of inversion symmetry across grain boundary affect the transport properties?

]]> 2021-02-15 13:49:03 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203700162 Magnetic field through grain boundaries https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203703656 Has the mobility/conductance through grain boundaries been compared with those properties within the grain under the effect of a perpendicular magnetic field?]]> 2021-02-15 13:50:08 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203703656 Has anyone systematically measured the effect of grain boundaries on the mechanical properties? - Aravind Aravind_Vijayaraghavan https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203703815 2021-02-15 13:50:12 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203703815 Sam D. : the GBs you considered contained a lot of disorder compared to the pentagon-hexagon pattern that one could observe, how would that affect your observation ? https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203759007 2021-02-15 14:08:38 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203759007 JS Lauret. https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203794910 What is the nature of the chemical bounds between the grains?

]]> 2021-02-15 14:20:27 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203794910 Chris E: Buckling https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203816224 Great talk! I'm curious, I guess you let the bounding box vary in size during optimisation of the disordered graphene, what's the typical reduction in size you see? And if you destroy the aromaticity, doesn't it want to crumple up and go "3D"?]]> 2021-02-15 14:26:52 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203816224 What is your explanation that a-BN has a very low-k? https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203818018 2021-02-15 14:27:26 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203818018 About the parameter q3: would you comment on what goes into its definition? is it a structure factor kind of quantity? Another related question: the data you showed us is averaged over different disorder configurations, i.e., for different spatial distribution of the domains? sandler1 https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203830998 Nancy]]> 2021-02-15 14:31:46 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203830998 Hi Stephan https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203856125 The 5-7-7-5 defect should not be named "Stones-Wales! - Marc M.]]> 2021-02-15 14:39:27 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203856125 Peter B: G on a-BN? peterboggild https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203863366 aBN compared to hBN - how smooth can aBN be? Will there not always be more dangling bonds, roughness and trapped states, for aBN to approach hBN as substrate/encapsulation?]]> 2021-02-15 14:41:31 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203863366 Nishaina Sahadev https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203892478 Thanks a lot Prof. Roche for the talk. Does the triatic order parameter consider the edge/boundaries of the graphene structure]]> 2021-02-15 14:51:14 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203892478 Thermal conductivity https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203904880 Would you expect a decrease in in-plane thermal conductivity of sp2 amorphous carbon monolayer when a second layer is stacked on top, as is observed in graphene due to scattering of out of plane phonon modes? Would such still exist in a truly amorphous monolayer? Shyam]]> 2021-02-15 14:55:20 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203904880 Fabrice Piazza: https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203926678 2021-02-15 15:02:47 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203926678 measuring thermal conductivity https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203929111 which thermal methods are capable of determining the properties of such amorphous materials and when applied to such thin films, are they free-standing? - Nat]]> 2021-02-15 15:03:33 UTC https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203929111 Nishaina Sahadev https://padlet.com/peterboggild/pgp4ifp0rrppv6qf/wish/1203932381 Sir, Does stacking of graphene layers affect the out-of-plane phonons than when they were in the isolated monolayer state

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