Graphene Definition and 189 Threads

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 ^^

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?

From what I'm hearing, graphene will change the way we live, work and play. Everything from cars and clothing to workplaces and weaponry will incorporate the stuff. Is this true, the hype of stock promoters or something in between? Which aspects of life will be the most affected by the use of...

Hi. Why Zigzag graphene nanoribbons is metallics??

Hi i saw some technics with sticky tape and pencils(i know its not pure graphite) but how can i take it a step further to produce more ?

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...

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...

Young’s modulus is given as the second derivative of the total energy with respect to the strain divided by the equilibrium volume. Can help me for the calculate equilibrium volume and young's modulus?

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?

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...

Can anyone explain what is tight binding method . I don't understand much .for solids mostly for graphene with one atom per site

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...

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...

Hi I have plot band structure zigzag graphene nanoribbons with Matlab. I do not know if it is properly written program anyone can help Bug fixes. NU=10; % Number of atoms Nbnd=4*NU; % number of bands aa=2.26; a=sqrt(3)*aa; Csoc=0.0; X(1)=0; Y(1)=0; for ixy=2:NU if mod(ixy,4)==2...

I am currently modelling van der Waals interactions using DFT-D as my undergrad thesis. The basic set-up is a molecule suspended above a crystal surface. To start the surface is graphene, which has been causing me some trouble as neither VMD nor VESTA are allowing me to visualise the set-up...

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...

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...

As far as I know, the Hamiltonian of graphene in the Bloch's sums |A\rangle and |B\rangle near the points K or K' is a 2 \times 2 matrix with the components: \langle A|H|A\rangle, \langle A|H|B\rangle, \langle B|H|A\rangle,\langle B|H|B\rangle which all are parameters (and not variables). But in...

Can help me for the write program for calculating nearest neighbours in graphene? Program the nearest neighbours for armchair graphene nanoribbon same as the follow: close all clear all clc L = 2; H = 4; lineatoms = 2 * H + 1; for i = 1:lineatoms if mod(i,2)==1 x(1,i) = .71; else...

Hello, I am interested in possibly fabricating microprocessors if I make it through school. I have yet to take my first course in organic chemistry. Will I have to know anything about organic chemistry if I am to fabricate microprocessors? Do you know if organic chemistry is employed in the...

Hello. I don't know much about the Graphene. I do know about this are 1. It is just a single layer of cabon bonding. 2. The mobility of electrons for Graphene is about 100 times faster than normal metal(right?) 3. It is very robust material better than diamond. In terms of its robustness, I...

Dear forum people The new position of the carbon atoms under uniaxial strain r in the framework of elastic theory is shown by the following equation: ri'=(I+ε).ri in which ri and ri' are the position of the carbon atoms before and after the strain is applied, respectively. I is the unit matrix...

Can someone recommend a good book on graphene?

I am encountering an issue when I plot attempting to plot 3d band structure of graphene in Mathematica. While the general shape and curvature looks fine, the cones at the K-points are not touching, which is an important qualitative electronic property of graphene. Since further down the line I...

Hi I have Hamiltonian matrix and overlap matrix. How to calculate tight binding dispersion for graphene in matlab? I would be appreciated if could some one give me a hand on my problem.

http://www.bbc.com/news/technology-32101473 The BBC reports that a graphene light bulb will go on sale. What are its advantages over current technologies?

I want to see if anyone has worked with this or know anything about this type of material? I am looking into particular the coating process of materials I.E. steel. Looking for processes and material specs. Any help would greatly be appreciated. Thanks

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...

Hello all Quickly, does anyone have an explanation if any for usage of silicon oxide in graphene visibility experiment?? I have a seminar presentation in one hour and I know its a possible question from one of the supervisors. Thank you

There’re 2 ways to calculate the subband structure of graphene nanoribbon using tight-binding model, for Zigzag chain: The first one is to diagonize the Hamiltonian $H = H_0 + H_10*exp(i*k_x) + H_01*exp(-i*k_x)$ and obtains the eigenvalues. The second method is just diagonize the Hamiltonian in...

Andre Geim & Co have discovered that graphene can act as a sieve which allows protons to pass through it, while blocking other atoms and molecules: http://www.independent.co.uk/news/science/scientists-predict-green-energy-revolution-after-incredible-new-graphene-discoveries-9885425.html...

Researchers from the University of Manchester were surprised to find that positively charged hydrogen atoms - protons - can pass through it http://www.independent.co.uk/news/science/scientists-predict-green-energy-revolution-after-incredible-new-graphene-discoveries-9885425.html Does that mean...

Hi I've made what I think is graphene. I first put the solution on cardboard and then I put some on polyethylene. When they had dried, I tested conductivity with a digital multimeter with the scale set on megaohms. The cardboard was nonconducting, but the sample on poly to my astonishment showed...

From A member of the Minnesota Futurist who is still looking at/ for? any thing Graphen

Basically, I've written some code that take as inputs 1)Basis vectors 2)lattice translation vectors and computes the structure factor of the basis, producing a diffraction pattern. I'd like to begin incorporating subtle differences between atoms, so I want to compute the structure factor of...

Copper conducts electricity and so does other metals like silver. Now a new material is coming to play which is graphene, But I was wondering in order to generate electricity must it be in copper coils? Can it be in silver coils, graphene coils? ^.^

Dear All, I have three questions about the relation between the K-points and energy cutoff. The first one is : how many k points should I use in my theoretical calculation to get a good result in lattice constant and the converge of E[SIZE="2"]min especially for using DFT? The second one is...

A lot of people have been arguing that TSLA's stock/the company in general won't take off because the demand is above the battery technology at this time. I'm a junior in college studying physics but will probably either switch to finance and do stocks because i like it more or i was double...

I'll just launch into it: I graduated recently from Temple University with a B.S in Physics, GPA 3.83. I worked in three labs, one semester each, during my studies: one for pay, one volunteer, and one for credit. In the first, I did analysis for Mossbauer spectroscopy; in the second, I produced...

Homework Statement Using the dispersion relation at the Dirac Point calculate the electron density of states for graphene in both the valence and conduction band. Homework Equations ρ = density of states = k2/pi2 The Attempt at a Solution I looked up what Dirac Points...

Hi All, I'm finishing up my PhD in Computational Condensed Matter. I've worked almost exclusively in spin systems using things like Monte Carlo and Exact Diagonalization. However, my specialty is in producing high-quality, high-performance, often parallel research codes (i.e. none of my...

Hello, I started this topic to discuss interesting new night vision technology that was presented on TED talks. Old, expensive and bulky IR (or other light spectrum) IIT amplifier could be replaced with very thin OLED based, cheaper and low power consuming image intensifier which was developed...

Hey everyone, I'm currently doing research at a University, I've been working on a problem for a few hours and wrote up a quick paper that shows my derivation of a certain height based on an angle. Basically the experiment is looking at optical properties of graphene, but for this to happen we...

Ok so I have a view ideas in mind for a project I was planning on doing involving genetic algorithms for my high school science fair class. I do have 3 mentors one a mathematician, a computer scientist who focuses on GAs, and a physicist who focuses on nano structures. here where I live, but...

Recently, reading an article about graphene, it was disclosed that a sheet of graphene the thickness of a piece of plastic wrap could support the weight of an elephant balanced on a pencil. Beyond the fact that I highly doubt anyone got an elephant (although good at balancing tricks I have seen...

Hello, I'm interested in research and development of either fusion power generation or graphene based nanoelectronics. One of the things I like about these areas is that they are in the imminent stages of development and I will probably see them developed in my lifetime. My issue is that...

Can we make exoskeletons out of CNTs? I have a few questions 1. Do CNTs expand when electricity is applied or you have to put wax betwen them? 2. Can we produce enough nanotubes to make a full-body suit? 3. Is graphene suitable for an armor? Some say that when you put a elephant on a...

I've gotten really interested in CFD and DFT recently. I have a BS in Chemical Engineering and will be 25 in about a month. Been working in the oil industry for the last 2 years and before that I worked in a carbon nanotube and graphene 'factory' for lack of a better term that I can come up with...

Hi everyone, I'm trying to fit the Tight Binding molecule for a more complicated system, so I'm first trying to understand it for a simpler one, graphene. I've read several guides but they're all confusing me. Right now, I'm trying to understand the graphene example on this site. My biggest...

The theoretical "Augmentations" One thing that is somewhat common and has to do with medical science and my interests are augmentations, robotic, nano-technological, or even sometimes genetic enhancements. In the science fiction representations people can outperform human strength and speed...