Imperial Journal of Interdisciplinary Research (IJIR)
Vol-2, Issue-8, 2016
ISSN: 2454-1362, http://www.onlinejournal.in
Rietveld Refinement and Strain
Analysis of SnSeNi0.4 Crystal
G K Solanki1, I L Chauhan2, K D Patel3 & K B Modi4
1, 2&3 Department
4Department
of Physics, Sardar Patel University, Gujarat, India
of Physics, Saurastra University, Rajkot, Gujarat, India
Abstract: Layered semiconductor crystals show
important application in the fabrication of energy
converting
devices.
SnSeNi0.4
is
layered
semiconductor crystal grown by Direct Vapour
Transport
(DVT)
technique.
Structural
characterizations like X-ray diffraction (XRD) with
Rietveld refinement, strain analysis from Gaussian,
Lorentzian and Pseudo-Voigt profile analysis,
Energy dispersive analysis of X-rays (EDAX) and
surface microstructure topography has also been
carried out.
1. Introduction:
Layered binary IV-VI semiconductor compounds
have been suitable for various optoelectronic
applications like memory switching devices,
photovoltaic, light emitting devices (LED) and
holographic recording systems [1-4].Physicists have
used layered compounds to discover and understand
novel phenomena of charge and spin density waves.
The understanding developed enabled subsequent
extension of these phenomena [2-3]. These kind of
layered compounds are materials having a large
anisotropy. Their temperature dependent electrical
and magnetic properties of layered material have
been important in the development of solid state
chemistry, physics and engineering applications.
Direct vapor transport (DVT) technique has been
used for the growth of SnSeNi0.4 crystals. SnSeNi0.4
crystals are structurally characterized by X-ray
diffraction, (XRD), Rietveld refinement, Energy
dispersive analysis of x-rays (EDAX) and Surface
microstructure topography. Lattice strain is a
measure of the distribution of lattice constants
arising from crystal imperfections, such as lattice
dislocations. Other sources of strain include the grain
boundary triple junction, contact or sinter stresses,
stacking faults and coherency stresses. Lattice strain
affects the Bragg peak in different ways. This effect
increases the peak width and intensity as well as
shifts the 2θ peak position accordingly. The uniform
and non-uniform effect of strain, on the direction of
X-ray reflection has been discussed [12]. Strain
analysis has been carried out from Gaussian,
Lorentzian and Pseudo-Voigt profile analysis. All
Imperial Journal of Interdisciplinary Research (IJIR)
these kinds of structural characterizations plays
important role to find out its crystallographic
structure, chemical composition as well as its surface
studies.
2. Experiment and Result:
Growth: Crystals of SnSeNi0.4 were grown by Direct
Vapour Transport (DVT) technique with the help of
two-zone, horizontal, temperature gradient furnace.
Chemically cleaned quartz tube closed at one end
having length 22 mm, outer diameter 21mm and
inner diameter of 20 mm, used for the growth of
SnSeNi0.4 crystals. This cleaned ampoule was filled
with Stochiometric proportion of Sn (99.99 %), Se
(99.999%) and Ni (99.999%) pure of about 10 g of
powder material then the ampoule was sealed at
pressure of 10-5 torr. The material charge was kept at
higher temperature zone i.e. Hot zone of the furnace
1,373 K while the growth of crystals took at lower
temperature zone i.e. Growth zone, 1,323K for 100
hours after at the rate of 10°C/hr the furnace was
allowed to cool down slowly to room temperature
[5]. After breaking the ampoule, large numbers of
crystals were obtained at the cooler end of the quartz
ampoule in the platelet form. From these crystals
some suitable crystals were selected for different
characterizations according to their surface and
dimensions.
3. X-ray powder diffractogram (XRD):
The X-ray powder diffractogram (XRD) was
recorded by using Rigaku Ultima IV X-ray
diffractometer by employing CuKα (1.54 °A)
radiation. For this purpose, many small crystals from
each group were finely grind with the help of agate
mortar and filtered through 106-micron sieve to
obtain grains of nearly equal size. X-ray
diffractogram for SnSeNi0.4 is shown in Figure 1 and
the calculated values of lattice parameters comes out
to be a=11.51A˚, b=4.15 A° whereas c=4.45˚A for
each sample and the value of c/a ratio comes out to
be 0.3866 which is approximately equal to 0.4. The
value of c/a ratio gives information about
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Imperial Journal of Interdisciplinary Research (IJIR)
Vol-2, Issue-8, 2016
ISSN: 2454-1362, http://www.onlinejournal.in
crystallization phase of crystal. Here the value of c/a
ratio (0.4) predicts that SnSeNi0.4 crystallize as FCC
phase.
analysis with help of XPowder Ver. 2010.01.45 PRO
software. Strain analysis gives size of crystallites in
crystal. Observed data has been listed in Table 1.
Table 1. Strain(%) analysis for SnSeNi0.4
Size (nm)
Full profile
Gaussian
0.293 (µm)
Lorentzian
0.134 (µm)
Pseudo-Voigt
0.146 (µm)
6. Energy dispersive analysis of x-rays
(EDAX):
Figure 1: X-Ray diffraction pattern of SnSeNi0.4
The value of X-ray density is 2.497 gcm3 and it is
matched with the JCPDS data [6]. The values of
lattice parameter clears that SnSeNi0.4 possesses
orthorhombic FCC structure. From Figure 1, a well
resolved X- ray peaks corresponding to the (400)
plane is observed for SnSeNi0.4 compound. This peak
proves the strong orientation along any one of the
axis which can be a, b or c and crystallization takes
place in the perpendicular direction to (400)
reflection plane. The intensity of all other reflections
is extremely weak.
It is very important to find out Stochiometric
proportion of elements in the formed compound
especially when doping entered into pure material.
For this Stochiometric characterization Energy
dispersive analysis of x-rays (EDAX) is used.
Chemical composition of SnSeNi0.4 has been listed in
Table 2. The wt% of elements obtained by EDAX
and calculated are approximately equal in value.
Table 2. Chemical composition of SnSeNi0.4 by
EDAX analysis
Wt% of element
Obtained by EDAX
calculated
Sn
Se
Ni
Sn
Se
Ni
55.13
36.68
10.90
55.14
36.65
10.70
7. Surface microstructure:
Figure 2: Rietveld refinement of SnSeNi0.4
4. Rietveld refinement:
A study of microstructures on several crystals of this
variety showed layered type of growth of crystal is
perpendicular to any one of the axis by using
‘Epignost’ optical microscope (Carl Zeiss Jena
GmbH, West Germany).A typical example of layered
growth which is a representative of all such
observations is depicted in Figure 3.
A Rietveld structure refinement has been done for Xray powder diffraction data of SnSeNi0.4 as illustrated
in the Rietveld plot in Figure 2. The Rietveld
refinement and synthesis experiment described here
forms part of a large study [5-7]. The raw diffraction
pattern was prepared for Rietveld refinement using
the General Scattering Analysis Software (GSAS).
The background was fitted with a polynomial curve;
an overall scale factor was also used.
5. Strain analysis:
Figure 3: A typical example of layered growth for SnSeNi0.4
An asymmetric pseudo-voigt line shape was
employed. Strain analysis has been carried out by
Gaussian, Lorentzian and Pseudo-Voigt profile
Imperial Journal of Interdisciplinary Research (IJIR)
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Imperial Journal of Interdisciplinary Research (IJIR)
Vol-2, Issue-8, 2016
ISSN: 2454-1362, http://www.onlinejournal.in
8. Conclusion:
In this paper authors have successfully grown
SnSeNi0.4 crystals by direct vapour transport (DVT)
technique. Surface microstructure study also been
carried out and it was observed that this crystal
possesses layered growth. Crystals having
orthorhombic structure confirmed from XRD,
Rietveld analysis and strain analysis profiles have
also been reported and EDAX characterization
proves that elemental proportions are compatible
with calculated values.
9. Acknowledgements:
This work was supported by a Department of
Physics, Vallabh Vidhyanagar & Department of
Physics, Rajkot, Sardar Patel University and Prof G
K Solanki, K D Patel and K B Modi.
10. REFERENCES:
[1] Marcela Achimovičová1, Aleksander Rečnik2, Martin
Fabián1 and Peter Baláž1, Acta Montanistica Slovaca,
16 (2011), 123-127
[2] David Johnson, Simon Clarke, John Wiley, Kunihito
Koumoto Semicond. Sci. Technol. 29 (2014) 060301
[3] J B Patel, M N Parmar, M P Deshpande, G K Solanki,
M K Agarwal, Indian Journal of Pure & Applied Physics,
43(2005), 527-531
[4] M.L.Knotek and M. Pollak, Phys.Rev.B, 9(1974)664
[5] Gokhan Bakan, Lhacene Adnane, Ali Gokirmak and
Helena Silva, J. Appl. Phys. 112(2012), 063527.1-9
[6] Jcpds card number SnSe 32-1382
[7] J. Ravichandran, J. T. Kardel, M. L. Scullin, J.-H.
Bahk, H. Heijmerikx, J. E. Bowers and A. Majumdar,
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015108.1-4
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