M.Sc. (Semester IV) (CBCS) Examination Oct/Nov-2017
Materials Science
ADVANCED TECHNIQUES OF MATERIALS CHARACTERIZATION
Day Date: Friday, 24-11-2017 Max. Marks: 70
Time: 02.30 PM to 05.00 PM
Instructions: Q. and Q. are compulsory.
Answer any three questions from Q.3 to Q.7.
All questions carry equal marks.
Q.1

Objective questions:
Choose the correct alternative:-
14
08
Wavelength of the electrons in transmission electron microscope is

4000-7000 A
1-100 mm
few A
electron being particle does not processes any wavelength
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 scatted electrons in SEM is that
of secondary electrons.
Equal to Greater than
Less than None of these
Wavelength of the electron in 200 kV TEM is
2.5 pm 2.5 A
2.5 nm 2.5 mm
In TEM is usually used as cathode material, which is acts as
a source of electron.
Tungsten Aluminum
Copper Nickel
Histogram is plot of
Number of particles Vs size of the particles
Energy of particles Vs size of the particles
Brightness of particles Vs size of the particles
Intensity Vs. Energy
The XPS, impinged onto the surface of material and
are ejected out.
High energy radiation, electrons
High energy ions, X-ray,
IR radiation, ions
Electron, phonon
Page 2 of 2
SLR-MO-542
The IR mode is active if and only if
There is net change in electric dipole moment
There is net change in polarizability
There is change in shape of the molecule
There is ejection of electron
State True or False/ Fill in the blanks: 06
As the accelerating voltage applied in case of SEM increases, the
penetration depth in the sample of the charges particle increases.
Backscattered electrons are as a result of inelastic scattering of
electron with nucleus of specimen atom.
To get good contract in SEM image, the signal from the feature of
interest should be less than that of background.
While recording the SEM image of an insulating sample, sample
surface get charges which need to be grounded.
In TEM electron beam transmits through the sample, which gives
structural information of the sample.
In order to increase the resolution of a microscope, one should
increase magnifier.
Q.2 Write short notes: 14
Optical microscope
Electron energy analyzer
Raman spectra of carbon based materials.
Q.3 What are the limitations of optical microscope? How those are overcome
in electron microscope? Explain what resolving power is and determine
the same for optical microscope and scanning electron microscope.
10
Explain polarizing light microscope. 04
Q.4 Explain the basic working principle of X-ray photoelectron microscopy
with the help of suitable example.
08
With the help of suitable example qualitative and quantitative analysis of
Auger electron spectrum.
06
Q.5 Explain in detail quantum mechanical description of NMR. 10
Explain Magic Angle Spinning (MAS). 04
Q.6 Draw schematic of TEM and explain working of each part. 10
What are secondary and backscattered electrons? What is their origin?
Where those are useful.
04
04
Q.7 Explain the following:-
Fluorescence microscope.
Rayleigh criterion
Electrostatic and magnetic focusing in SEM.
10
Maintain the methods used for vibration oscillation in STM. Explain one
of them in detail.