Read about graphene | 133 Discussions | Page 1

  1. S

    A Graphene's Hubbard U and nanotube's U

    PhysRevLett.106,236805 (2011) seems to state that Graphene has U=9.3eV and PRB 55-R11973 (1997) states that nanotube has U=u/N. However, it's not unusual for them to be hubbard U systems
  2. SpinzTronics

    Help searching for SAMs (self-assembling monolayers) for a project

    Does anyone know of a self-assembling monolayer that can bind to triethylamine,deposit onto graphene/TMD by evaporation, and that has "low toxicity" (that I could use in the lab)? P-dopants could only help dope one side of the material and TEA would react on the other but that is very hard to...
  3. Sadek

    Permitivitty of graphene

    i'm working on a project about the surface plasmon in graphene. i found on some articles that we don't use Drude model to calculate permitivity on graphene but they didn't mention what's the right model ! can you help me please and give me the relation that link links between permitivity and...
  4. Javier Lopez

    B What is the work function of graphene sheets?

    I have found different values depending where is read. I should like have a graphene sheet on copper to be used in a ionizer to generate lots of electrons
  5. D

    B Can graphene be used as a template for graphene growth

    Hi, If I had a silicon carbide wafer Si-face with a monolayer of graphene on it, then spin-coat it with single wall carbon Nano tubes (CNTs) onto the graphene and then annealed it, would the CNTs bond to the graphene under them? Or would they still partially unzip and decompose forming a sheet...
  6. Nod

    A Charge density of carbon nanotubes and graphene

    Hi everyone! I'm trying to solve the following problem: given the charge densities of carbon nanotubes and graphene, the charge density difference of 2 systems must be found. So I need to unfold in some way the nanotube and compare it charge density with the graphene's one. But how this...
  7. K

    Ell Donsaii series

    I saw a previous thread on this had been closed without going anywhere. The Ell Donsaii series is, I consider, a fiction must read for anyone in the physics and A.I. fields. Much of the "fiction" within is becoming fact, almost on a weekly basis. When the series began, we had no Alexa or...
  8. S

    How do I get this interface condition?

    Homework Statement I have an infinitely long cylinder of a dielectric material, surrounded by another dielectric material and coated with graphene which has surface conductivity \sigma, implying it has a superficial current. The sheet of graphene is very thin, and the dielectrics are asumed to...
  9. J

    Standard Enthalpy of formation of Graphene

    I am curious as to what the Standard Enthalpy of formation of Graphene is. I've noticed several highly technical papers on this subject but I got lost in the abstruse math and terminology. I am interested in the Standard Enthapies o both single layer and multi-layer graphene. I will be happy to...
  10. G

    How to calculate the current in a 400 nm wire of graphene

    Hi, I need to calculate the current in a 400nm piece of graphene. Can some one help me please? I found online that graphene has electron mobility of 200,000 cm^2/( V s). My best attempt is as follows. Using the equation vd = uE where E is the magnitude of the electric field applied to a...
  11. S

    I How can I obtain the reciprocal lattice of graphene?

    I have a question about reciprocal lattice of graphene. When we see LEED pattern, we can know that reciprocal lattice of graphene is honeycomb. But how can we know theorically that it is honeycomb? Hexagonal lattice or other bravais lattice has just lattice vectors which don`t contain baises. So...
  12. C

    Tensile Strength of reduced graphene oxide?

    Does anyone know the tensile strength and other mechanical properties of reduced graphene oxide? I know that it has some similarities to both graphene and graphene oxide, but I can't find any data on its tensile strength.
  13. T

    I How is Graphene's Hamiltonian rotationally invariant?

    Graphene's Hamiltonian contains first order derivatives (from the momentum operators) which aren't invariant under simple spatial rotations. So it initially appears to me that it isn't invariant under rotation. From reading around I see that we also have to perform a rotation on the Pauli...
  14. S

    A What is the charge neutral point?

    I have a question about definition of charge neutral point. I`m reading some article about trilayer graphene, and this term, charge neutral point, is used in the article. I googling this word, but I can`t find something which can tell me what it is. In monolayer graphene, what i found by...
  15. H

    I Why perfect graphene has nonmagnetic state?

    I'm major in chemistry my undergraduate.. and not good at Physics, Solid states... etc. I know pure graphene has two sub-lattice because it has two carbon atoms.. and something basic properties. then, why perfect graphene(no vacancy) is in nonmagnetic?
  16. I

    Graphene work function

    Is the reciprocal of the work function of ' Graphene ' a usable tool for the calculation of the electrical pressure * capacity or even an indicator of co-conductivity of a given area of (magnetically oriented) Graphene in relation to a substrate material which is also conductive ?
  17. A

    Congratulations Mechanical Engineers

    People spend so much time drooling over the millions or even billions made by software tycoons and their sometimes very crappy software, that we may forget about the tangible accomplishments of mechanical engineers. Here is a beautiful example. Do you have more...
  18. C

    I Graphene substrate

    I have looked on the internet but not found a clear anwser. can graphene sutstane its 2-dimensional form witout anny help froms substrades? tanks for helping ^^
  19. R

    I Carbon in air to graphene?

    Is it feasible to turn the abundance of carbon in the atmosphere into graphene, given it is an allotrope of carbon and would it be worth the trouble?
  20. N

    A Is graphene a Weyl semimetal?

    I'm recently interested in the topological/Weyl semimetals, but I'm not an expert on the theory. Most papers just define Weyl semimetal as a material that have pairs of Weyl points with opposite Berry curvature. Here in graphene, the Berry curvature of the Dirac cones at K and K' point is also...
  21. S

    A Wavefunction matching two different H, not just V

    Can the basic techniques of wavefunction matching that one would use to calculate the transmission through a step barrier potential and the Dirac hamiltonian of graphene be used for a situation where instead the fermi velocity changes in a step like fashion. i.e. instead of a Hamiltonian like...
  22. Harry Smith

    I Will ethanol destroy double layered graphene?

    I am doing a lab and we get silver epoxy resin on our double layered graphene sample where we didn't want it. We can take off the silver paint using ethanol but worry it may destroy the thin layer. Will ethanol be okay to use? Are there any suggestions on what to use?
  23. A

    Making a Graphene suit

    So I have heard about graphene and its properties recentlty and more specifically its ability to resist tearing. With this in mind (and a video from the YouTube channel "Film Theory") I believed it was possible to stack layers of graphene so that they can resist things like bullets. But I...
  24. thund3rcz

    I Effect of SAM physisorbed on graphene - some questions

    Hello everyone! :) I'm sorry that I'm posting something that might be obvious, but I'm still struggling to capture all the concepts behind the fundamental physics of this model. Let's say, I have a 2D sheet of graphene, on which, theres a physisorbed layer of molecular dipoles (vdW bonding, no...
  25. T

    Graphene questions

    Hi, I haven't had any chemistry exposure for over a decade, (I have some semi-conductor and quantum mechanics experience though) I was wondering: (to my vague 'knowledge') If graphite is just made of many overlapped graphene sheets, then why isn't graphite conductive? Also, if graphene is a "2D...
  26. E

    Graphene structure obtaining code

    I want to write a octave code(It can be another language I want to know how should I think to write a such a code ) to obtain graphene structure like in the figure. This code should give me a graphene sheet which in size I want when I enter the position of the atoms in the lattice.I think that...
  27. J

    What laser should I use?

    If I were to replicate this experiment http://arxiv.org/pdf/1505.04254v1.pdf but was limited to the purchase of only one laser which frequency and what power should I choose? I know the research team that conducted this experiment purchased their lasers from jetlasers.org but they unfortunately...
  28. T

    Book recommendation on fundamental physics in Graphene

    I am a condensed matter grad. student, but do not work on Graphene. I am interested in learning about the fundamental physics in graphene (e.g. the need to use Dirac equation to represent the motion of electrons). I know that many books are there, but not all are geared towards fundamental...
  29. Benevito

    Solid State Introductory book on graphene?

    Can someone recommend a good book on graphene?
  30. F

    Why is graphene placed in a cryostat in research?

    I have been told when making transport measurements of graphene it is usually placed in a cryostat and cooled to ~ 4K. However I cannot find any sources that back this up and don't fully understand why it is done in the first place. My thoughts are that it is to measure the carrier mobility...
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