M.Sc. (Semester IV) (CBCS) Examination Mar/Apr-2018
Physics (Materials Science)
ADVANCED TECHNIQUES OF MATERIALS CHARACTERIZATION
Time: 2½ Hours
Max. Marks: 70
Instructions: Q.1 and Q.2 are compulsory. Attempt any three questions from Q. 3 to 7. All questions carry equal marks.
Q.1

Choose the correct alternative:
08
Raman spectroscopy deals with
Transition of electron between two vibrational energy states
Transition of the electron between two electronic energy states
Absorption of electron from source
Photoelectric effect in IR range of electromagnetic spectrum
The resonance frequency range for electron in case of ESR is close to
10 GHz
100 MHz
100 GHz
100 Hz
Absorption of energy from electromagnetic radiation by a molecules gives
Stokes line
anti Stokes lines
Rayleigh line
None of these
Charge on X-ray is
1.6×10−19𝐶
−1.6×10−19𝐶
Neutral
9.1×10−31𝐶
In scanning electron microscope are impinged on the sample surface to get the surface information.
Electrons
Photons
X-rays
Phonons
The energy of the back scattered electrons in SEM is that of secondary electrons.
Equal to
Greater than
Less than
None of these
Histogram is plot of
Number of particles Vs size of the particles
Energy of the particle Vs size of the particles
Brightness of the particle Vs size of the particle
Intensity Vs Energy
Wavelength of the electron in 200 kV TEM is
2.5 pm
2.5 A
2.5 nm
2.5 mm
Page 2 of 2
SLR-UN-491

State True or False
06
In Auger electron spectroscopy, electron is emitted during secondary processes after emission of first electron.
For a linear molecule, symmetric stretching mode is IR active and Raman inactive.
AFM image looks brown in colour because the sample emits brown coloured radiations.
It is possible to record STM images in normal environmental conditions.
While analyzing SAED pattern energy of the scattered energy is mapped and analyzed.
It is possible to image an atom using SEM.
Q.2
Write short note on:
14
Resonance condition in ESR NMR
IR and Raman active modes
Contact and non contact modes in AFM
Q.3
Explain the process of image formation in scanning Tunneling Microscopy (STM). Also explain different parts and their working in detail.
10
Explain what is selected area electron diffraction (SAED) also elucidate its use in materials characterization
04
Q.4
Explain classical and quantum approach used to understand Raman Spectroscopy.
10
Explain acoustic and optical phonon modes.
04
Q.5
What is EPR condition? Explain in detail continuous wave EPR and EPR line width.
08
Explain the necessity of high resolution NMR spectrometer for solid samples, if any
06
Q.6
Draw the block diagram of AFM and explain the working of each part of the microscope.
08
Draw the force curve, which governs the image formation in AFM and explain the same.
06
Q.7
What do you mean by surface? What are different probes used for surface characterization. What is order of vacuum required to record the XPS spectra and why?
08
Explain what are bright field and dark field images in TEM. How do they are formed?
06