Thermal and DC electrical properties investigations of xSnO2 (50-x) PbO: 50V2O5(X=5, 10, 15 in molar ratio) glasses were carried out using X-ray diffractrometer (XRD), Differential scanning calorimetry (DSC) and two probe techniques. XRD results shown that the Perfect vitrification has been achieved and DSC results have indicated that the substituent SnO2 is replacing PbO in the glass network in such a way that the eutectic composition is maintained. The DC electrical conductivity studies on SnO2 substituted glass systems annealed at 1500C as well as 2250C and 3800C indicated that the conductivities increased as the annealing temperature is increased. activation energies also changed as the annealing temperature is changed.

1. Effect of annealing temperature on dc electrical conductivity properties of SnO2 doped lead vanadate glass system
IRJMSE
Effect of annealing temperature on dc electrical conductivity
properties of SnO2 doped lead vanadate glass system
*1Ponnada Tejeswararao, 2Balireddy Vasundhara
1,2
Department of physics, GITAM Institute of technology, GITAM University, Visakhapatnam, Andhrapradesh,
India
Thermal and DC electrical properties investigations of xSnO2 (50-x) PbO: 50V2O5(X=5, 10, 15 in
molar ratio) glasses were carried out using X-ray diffractrometer (XRD), Differential scanning
calorimetry (DSC) and two probe techniques. XRD results shown that the Perfect vitrification has
been achieved and DSC results have indicated that the substituent SnO2 is replacing PbO in the
glass network in such a way that the eutectic composition is maintained. The DC electrical
conductivity studies on SnO2 substituted glass systems annealed at 1500
C as well as 2250
C and
3800
C indicated that the conductivities increased as the annealing temperature is increased.
activation energies also changed as the annealing temperature is changed.
Keywords: XRD, DSC, DC Conductivity, annealing temperature, semiconducting glasses
INTRODUCTION
In the conventional silicate-based glasses electrical
conduction takes place due to ionic transport. In semi-
conducting glasses the electrical conduction is due to the
transport of electrons from low valancy state to high
valancy state (Mott N.F, 1968; Austin I.G et al,1969; Sayer
M et al,1972; Chung C.H et al, 1980; Ghosh A et al,1986).
The research in understanding the structural and physical
properties of glasses in general and semi-conducting
glasses in particular has increased considerably due to the
potential applications perceived for semi-conducting
glasses. Some of the possible applications are in
threshold switching, memory switching, electrochemical
batteries etc. Studies are carried out on semi-conducting
glasses in bulk as well as thick film form. Among all PbO-
V2O5 glasses have been of great interest due to their ease
of preparation (Ghosh A,1988; LivageJ et al, 1990; Sakuri
Y et al 1985; Peng B et al, 2005) as compared to other
semiconducting glasses.
In the present work, we prepared the glass samples by
adding SnO2 in different molar ratios into a chosen glass
matrix ((50-x) PbO: 50 V2O5) and discussed the study of
compositional and temperature dependence of D.C.
electrical properties of SnO2 substituted lead vanadate
glasses in the temperature range 300K to 500K.
Experimental
A series of glass with the molar formula x SnO2 (50-x) PbO:
50 V2O5 (X=5, 10, 15 in molar ratio) were prepared.
Appropriate amounts of reagent grade SnO2, PbO and
V2O5 were well mixed and melted in silica crucibles using
an electrical furnace at a temperature ranging between
9500C-10000C range, depending on the glass
composition. The melt was swirled frequently to insure the
homogeneity the melts were quenched on a large
stainless-steel block maintained at room temperature
(≈300C) and constituting of 9mm cylindrical cavities to get
samples of cylindrical shape of 2 to 3mm width. The glass
samples were annealed at 1500C below the glass
transition temperature for nearly 2 hours. The samples
were washed with an acetone and dried. The glasses were
stored in desiccators until required
In the present studies, XRD recordings of the powdered
glass samples were recorded with the help of a PAN Alytic
X’Pert-PRO diffractrometer using Cu Kα radiation at
1.5418Ǻ and diffractrometer settings in the 2θ range from
100C-700C by changing the 2θ with a step size of 0.020.
The density (D) was determined at room temperature
using Archimedes principle. The samples were weighed
*Corresponding author: Ponnada Tejeswararao,
Department of physics, GITAM Institute of technology,
GITAM University, Visakhapatnam, Andhrapradesh, India.
E-mail: blue.teja@gmail.com
International Research Journal of Materials Science and Engineering
Vol. 4(1), pp. 035-039, April, 2018. © www.premierpublishers.org. ISSN: 1539-7897
Research Article

2. Effect of annealing temperature on dc electrical conductivity properties of SnO2 doped lead vanadate glass system
Tejeswararao and Vasundhara 036
Using an electrical balance (Dhona Model 200D) of 0.0001
gm accuracy. The weight loss was measured in an
acetone (Aldrich) of 99.5% Purity and density 0.789
gm/cm3.
In the present studies, DuPont, USA make model 2000
thermal analyzer was used to determine the glass
transformation temperature (Tg), crystallization
temperature (Tc) and melting temperature (Tm). DSC scans
were conducted using 5-10 mg ground as-cast glass
specimens which are heated with heating rate of 100C/min
between 0 and 6000C in a platinum crucible. Alumina
powder was used as the reference material. The DC
electrical conductivity studies were carried out by using a
two-probe technique. A homemade muffle furnace using a
super kanthal wire as a heating element was used for
temperature variation studies in the range 300K – 500K.
Temperatures of the furnace as well as the sample are
monitored by using a Cr – Al thermocouples. The
resistance of the samples was measured using a Keithaly
(Model 614) digital electrometer. The conductivity was
calculated from a knowledge of the geometry of the sample
using the expression.
𝝈 = (t/Rx ) A (1)
Where RX is the resistance, t is the thickness and A is the
area of the sample.
RESULTS AND DISCUSSION
The X-ray diffractograms annealed at 150°c and 2250c
containing (x=5, 10, 15 mole %) of SnO2 showed no trace
of crystallinity and are shown in Figure 1 and Figure 2.
The X –ray diffractogram of sample annealed at 3800C is
showing crystalline peaks (Figure 3).
Figure 1. X- ray diffractograms of xSnO2 (50-x) PbO:50V2O5 Figure 2. X- ray diffractograms of 15SnO2 35PbO:
glass system annealed at 1500
C 50V2O5 glass system annealed at 2250
C.
(a) x= 5 mole% (b) x=10 mole% (c) x=15 mole%
Figure 3. X- ray diffractograms of 15SnO2 35PbO: 50V2O5 glass system annealed at 3800
C.

3. Effect of annealing temperature on dc electrical conductivity properties of SnO2 doped lead vanadate glass system
Int. Res. J. Mat. Sci. Engin. 037
The DSC patterns for these glass systems shown in Figure
4 are slightly different when compared to the unsubstituted
system (Ramesh K.V, 2000). Values of glass transition
temperature Tg, crystallization temperature Tc, melting
temperature Tm, glass forming tendency Kg and densities
of the xSnO2 (50-x) PbO: 50V2O5 are given in Table1 and
these results suggest that SnO2 acts as a network modifier
where as PbO acts as a network former. As seen in Figure
4 up to x= 15 mole% there is only one endothermic peak
corresponding to melting point. This indicates that the
substituted samples behave like the eutectic composition
up to x=15 mole%.
Figure 4. Differential scanning calorimetry curves of xSnO2
(50-x) PbO: 50V2O5 glass system.
(a) x= 5 mole% (b) x= 10 mole% (c) x=15mole%
In order to understand the devitrification tendency and
thermal stability of the glass samples, glass forming
tendency values Kg are calculated using the following
equation.
Kg = (Tx - Tg) / (Tm – Tx) ------------ (2)
Where Tx is the beginning of the first exothermic reaction
where the crystallization starts. Lower value of Kg indicate
that the tendency of crystallisation is more and thermal
stability is less. (Tejeswararao P et al, 2016). Kg
represents the temperature interval during nucleation. the
experimental values indicate that the 5SnO2
45PbO:50V2O5 glass samples have lowest thermal
stability among four compositions, with a Kg value of 0.099.
The densities seem to be increasing with an increase in
SnO2 substitution (Tejeswara Rao P et al 2012) The
logarithmic DC conductivity (log10) as a function of
reciprocal of temperature for the three different values of x
(the molar fraction of dopant) is given in Figure 5 for
samples annealed at 1500C. At a given temperature the
conductivity increases as SnO2 substitution increases. The
SnO2 substituted glasses exhibit higher activation energy
when compared to those of 50 PbO: 50V2O5 system.
Figure 5. Temperature dependence of logarithmic
conductivity of xSnO2 (50- x) PbO:50V2O5 glass
system annealed at 1500
C.
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4
-5.5
-5.0
-4.5
-4.0
-3.5
-3.0
-2.5
-2.0
log10
(ohm
-1
cm
-1
)
1000/T(K
-1
)
x= 5% SnO2
x=10% SnO2
x=15% SnO2
x= 0% SnO2
Figure 6. Temperature dependence of logarithmic
Conductivity of xSnO2 (50- x) PbO: 50V2O5 glass
system annealed at 2250
C.
When the samples were annealed at 2250C for two hours,
(Figure 6) the conductivity behaviour seems to be similar
to that of the samples annealed at 150 0C except that all
the samples exhibit higher conductivity (Figure 5). The
conductivity still increases as concentration of SnO2
substitution increases. The activation energy remains
almost the same for all SnO2substituted samples. T. The
conductivities were also measured for the samples
devitrified after annealing at 3800C for five hours (Figure
7). There is a drastic increase in conductivities of all the
samples. The conductivities of the substituted samples still
seem to increase with an increase in the amount of SnO2
substitution.

4. Effect of annealing temperature on dc electrical conductivity properties of SnO2 doped lead vanadate glass system
Tejeswararao and Vasundhara 038
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4
-2.6
-2.4
-2.2
-2.0
-1.8
-1.6
-1.4
x=5% SnO2
x=10% SnO2
x=15% SnO2
x=0% SnO2
log10
(ohm
-1
cm
-1
)
1000/T(K
-1
)
Fig. 7. Temperature dependence of logarithmic
conductivity of xSnO2 (50-x) PbO:50V2O5 glass system
annealed at 3800
C
Table 1. Values of glass transition temperature (Tg),
crystallization temperature (TC), melting temperature(Tm)
and glass forming tendency (K g ) for the xSnO2 (1-x)
PbO:50V2O5.
Glass Composition
(mole %)
Temperature(0
C)
V2O5 PbO SnO2 Tg (0
C) Tc (0
C) Tm (0
C) Kg
50 50 ____ 241 300,412 500 0.156
50 45 5 253 292,390 496 0.099
50 40 10 251 294,391 495 0.134
50 35 15 248 287,385 494 0.138
But the conductivities of all the devitrified samples seem to
be less than that of the devitrified 50 PbO: 50V2O5 system
at higher temperatures. However, activation energies of
SnO2 substituted devitrified samples seem to be less than
that of the 50 PbO: 50V2O5 devitrified sample. The
activation energies obtained in the present studies are
given in Table 2.
The dependence of conductivity and activation energy on
the annealing temperature in the present studies indicates
a strong micro structural dependence.
Table 2: Activation energies obtained at different
temperature regions by fitting Mott’s model for SnO2
substituted lead Vanadate glasses.
Glass
composition
(mole %)
Activation
energies of
the samples
annealed at
1500
C
W(eV)
Activation
energies of
the samples
annealed at
2250
C
W(eV)
Activation
energies of
the samples
annealed at
3800
C
W(eV)
V2O5 PbO SnO2
50 50 ----- 0.175 0.143 0.155
50 45 5 0.339 0.341 0.067
50 40 10 0.302 0.350 0.096
50 35 15 0.296 0.358 0.106
The microstructure of the glass network may be varying
such that new conducting path ways are established. In
literature there are examples for such micro structural
dependence of conductivity. Chung and Mackemzie
studied electrical properties of 55V2O5:45GeO2 and 55
V2O5:45TeO2 glass systems (Murawski L et al,1979). They
should showed that the conductivities and activation
energies of the samples changed depending on the
temperature of melting which changed the V4+ ion
concentration relative to total vanadium ion concentration.
They also observed that the conductivities and activation
energies changed as the annealing temperature
increased. However, it must be mentioned here that SnO2
doped lead meta vanadate glasses in the present studies
exhibit much higher conductivities and lower activation
energies when compared to 55V2O5:45GeO2 or
55V2O5:45TeO2 samples reported by Chung and
Mackezie (Murawski L et al,1979) and also observed that
the conductivities are increasing as the annealing
temperature is changing in the increasing order (1500C-
2250C-3800C). We consider the above temperatures for
annealing the samples to understand how the conduct
ivies are changing at near the glass transition temperature
(2250C) and crystallisation temperature (3800C).
Kinser and Wilson (Kinser D.L et al,1972) studied the
electrical properties and the corresponding
microstructures of vanadium phosphate glasses and
suggested that the observed conductivity maximum at C
(Concentration of V4+/V Total)< 0.5 is a consequence of
micro structural segregation. Similarly, according
Anderson and Mac Crone in iron silicate glasses the
majority of iron ions are supposed to be situated in
relatively well-ordered clusters which might be giving rise
to high electrical conductivity in these glasses (Anderson
R.A et al, 1974). In literature there are instances of V2O5
containing glasses showing maximum conductivity at
different values of C (Concentration of V4+/VTotal) (Austin
I.G et al, 1969). These differences are attributed to
Polaron- Polaron interactions and short range coulomb
repulsion which modifies C in Mott’s equation (Sayer M et
al,1972) to C (1-C)n. These examples suggest that
diffusion like conduction mechanism in the glass systems
containing random distribution of ion sites may be
inappropriate. These discrepancies are supposed to be
explained by a model proposed by Anderson and Mac
Crone (Anderson R.A et al, 1974). In which the charge
carriers are supposed to move along paths along high
conductive chains of transition metal ions. Therefore, it is
possible in the present glass systems such conductive
chains of transition metal ions might be existing and these
conductive chains may be micro structural dependent and
vary as microstructure varies as a function of temperature.
CONCLUSIONS
Perfect vitrification has been achieved for all the glass
samples as can be seen from their X-ray diffractograms of

5. Effect of annealing temperature on dc electrical conductivity properties of SnO2 doped lead vanadate glass system
Int. Res. J. Mat. Sci. Engin. 039
the as prepared samples after annealing at 150o C and
225oC for two hours. DSC recordings show that eutectic
composition of the lead meta Vanadate has been
maintained for all the glass systems up to 15 mole% of
substitution. The DSC data also indicates that all the glass
systems are characterized by more than one crystallization
peak. This can be thought that of as an evidence for the
existence of more than one meta stable phase in the glass
systems. The dopant SnO2 is not divalent oxides like PbO.
Besides SnO2 is known to be glass formers unlike PbO
which is considered to be a glass modifier. In spite of these
differences, the present observations indicate that these
substituents are replacing PbO in the glass network in
such way that the eutectic composition is maintained and
the final devitrified system has a crystal structure that is
similar to that of lead meta vanadate. The DC electrical
conductivity studies on SnO2 substituted glass systems
annealed at 1500C as well as 2250C indicated that the
conductivities increased as the annealing temperature
increased. The activation energies also changed as the
annealing temperature is changed. These differences are
attributed to not only a change in the value of C
(concentration of V4+/total vanadium concentration) but
also a change in the microstructure of the glass system.
However, all devitrified glass samples annealed at 3800C
show increased conductivity which is attributed to increase
in the order of the crystalline system which reduces
scattering of the electrons in their conduction paths.
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Accepted 16 December 2017
Citation: Tejeswararao P., Vasundhara B. (2018). Effect
of annealing temperature on dc electrical conductivity
properties of SnO2 doped lead vanadate glass system.
International Research Journal of Materials Science and
Engineering, 4(1): 035-039.
Copyright: © 2018 Tejeswararao and Vasundhara. This
is an open-access article distributed under the terms of the
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