Rajaji Vincent

7 Questions 9 Answers 0 Followers

Questions related from Rajaji Vincent

What is Raman intensity? Is it height of the peak? or Is it area under the peak?

When we fit (Lorentzian or Gaussian) the Raman peaks, we will get the following three parameters. 1. height, 2. Area under the peak, 3. width. Out of 1 (height of the peak) and 2 (area under the...

02 February 2018 7,671 3 View

Why nano crystal shows broader Raman line width?

I would like to illustrate the above question with XRD technique. For example, width of the Bragg’s peak in XRD is inversely proportional to crystallite size, hence one I can expect increase in...

03 March 2017 5,597 6 View

How phonon softening is related to second order structural transition?

I would like to explain this question with following description. The system (crystal) can be perturbed by pressure, temperature, etc. Then the crystal may undergoes structural transition (from...

02 February 2016 4,546 3 View

How do we experimentally identify the anisotropy in the crystal?

I would like to explain this question with the following illustrative example. The semiconducting layered chalcogenides adopt hexagonal structure (Eg: Bi2Se3, Bi2Te3, Sb2Te3 etc.,) They have...

02 February 2016 6,418 2 View

What is the physical significance of derivative of bulk modulus?

In the high pressure XRD, pressure versus volume data is fitted by Birch-Murnaghan equation of state (BM-EOS). The fit will yield bulk modulus (B0), derivative of bulk modulus (B0’) and volume at...

02 February 2016 7,133 4 View

What will be the effect of electric field on Raman mode frequency and it’s FWHM (Full Width at Half Maximum)?

The study of external perturbation to the Raman modes is very novel and well understood. For example, pressure and temperature effects on solid are given below. Pressure effects: 1. The...

01 January 2016 2,137 2 View

How can we identify and differentiate between electron - phonon coupling and phonon - phonon coupling through Raman scattering measurement?

Generally, the line width (full width at half maximum) of Raman peak signifies the life time of phonon as FWHM is inversely proportional to life time. This life time may increase/decrease...

01 January 2016 8,754 7 View