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Questions related from Vk Singh
I know that wave-packet is the super-imposed form of the waves. It is created when some waves have interference and a particle (say electron) can be represented by a wave-packet. I am bit confused...
07 July 2019 9,719 34 View
I know that when we plot band structure i.e E vs. k, the shape is parabolic. But when we plot band structure for E vs k, where k is different points (gamma, M, K or K') of Brillouin zone edge...
07 July 2019 1,118 3 View
Generally we say that the density of states (DOS) at Fermi level contribute to many phenomenon. However in the Dirac cone DOS is zero at Fermi level. What does it mean and what are its...
07 July 2019 7,540 4 View
Why molecular beam epitaxy (MBE) is not called atomic beam epitaxy and how it differs from sputtering in growth sense? Can one grow sample in sputtering instead of MBE without changing any growth?...
04 April 2019 8,335 10 View
electron and hole effective mass
02 February 2019 7,879 5 View
Can an oxidized thin film sample get de-oxidized if put in the vacuum?
01 January 2019 8,288 14 View
Why in TIs, AFM image show triangular shaped terraces instead of hexagonal shaped? The terrace height could be 5-8 nm. does it means that there is no growth (no material) between two triangle gap...
10 October 2018 7,235 2 View
What is physical meaning of activation energy? I know that the activation energy can be estimated by Arrhenius equation. It has been observed that the activation energy is usually less than the...
10 October 2018 4,395 5 View
why in case of Graphene and other 2D materials spin is called as psuedospin? and how to we get other degree of freedom called valley degree of freedom? Please give simple explanation! Thank you
10 October 2018 6,937 3 View
Can someone help me in etching TGMR? I try chemical etching but not able to etch it. Is there another way?
07 July 2018 9,776 1 View
It was seen that when magnetization is in the direction of current flow, resistance is minimum and vice versa. Why resistance increases when spins are aligned and why it decreases when spins are...
11 November 2017 4,991 7 View
How one can remove capping from a thin film? I waould like to do transport measurements, without capping it seems that the magnetic layer gets oxidized and if one uses capping then how to perform...
08 August 2017 8,284 3 View
I am interested in oxides materials having very high dielectric constant. Can somebody suggest me some materials? Thank you
04 April 2017 6,342 3 View
The thin film quality on MgO substrate is not good. Is MgO substrate need to clean before deposition? How can we clean it?
03 March 2017 4,051 5 View
Could any one comment on the choice of substrate for thin film deposition using sputtering technique? is it necessary to choose the substrate with same lattice constant as that of material or any...
07 July 2016 7,489 4 View
if the orientation of substrate is not matching with structure of the material. what structure (surface morphology) thin film will show? will it show that of substrate orientation?
06 June 2016 8,854 8 View
researchers are using AFM,TEM,SEM or STM to know the surface topography of the films/materials. Could any one clarify which techniques among these is better and why? Thank you
06 June 2016 9,259 5 View
I want to measure sheet resistance of thin film. when I measure the resistance by multimeter, it shows 0L (??). can I measure its surface resistance? secondly, I have confusion, that which...
06 June 2016 7,510 7 View
which technique is suitable to know the elemental composition in a 30-50nm thin film? I heard that WDX (wavelength dispersive X-ray) could be used. Is it good technique for this purpose? please...
06 June 2016 950 16 View
Researchers are very excited for TIs which show some unique properties such as spin momentum locking and large spin-orbit interaction. they say spins are 100% intrinsically polarized in TI. I have...
06 June 2016 1,858 11 View
how the inhomogeneity and surface/interface roughness in thin films can be differentiated? how they can be identified? please explain it in simple way. Thank you
04 April 2016 9,588 0 View
Please help me how one can determine the position of chemical potential by knowing the 2D carrier density in topological insulators? Thank you
12 December 2015 4,107 1 View
Hi, What are the sources of error in thin film lattice parameters calculations? On calculating the lattice parameters from peak position, I am getting slightly different lattice parameters from...
12 December 2015 2,811 3 View
How to measure thickness of thin film using AFM? I have see some people have determined thickness of thin film using AFM. I have also tried but found that thickness is changing with changing the...
11 November 2015 4,434 24 View
