Authors : Daivajna M.D. and Shetty S.
Page Nos : 215-218
Description :
We report structural and electrical studies of Pr
0.6
Sr
0.4
Mn
1
-
x
Bi
x
O
3
(x=0,0.1 and 0.2)
manganites. In manganitesMn ions play a crucial role in shaping the physical properties. Possible
reasons for the observed structural, changes of resistivity behavior with Bi doping are discussed.
Replacing trivalent Bi ion with Mn ion
provides us a system to understand weakened double
-
exchange
(DE) interaction (Mn
3+
-
O
-
Mn
4+
). X
-
ray powder diffraction showed that all synthesized samples are single
phase and crystallize in the orthorhombic symmetry with
Pnma
space group.
The unit cell
volume
decreases with increasing Bi content
.
The value of metal
-
insulator (M
-
I) transition temperature (T
MI
)
decreases and resistivity increases as doping level x increases. The drop in
resistivity
at
T
MI
results from
the reduced contribution of magnetic sca
ttering. Ferromagnetic metallic resistivity is observed well below
the metal
-
insulator transition temperature. Above the metal insulator transition temperature the
electrical conductivity is dominated by small polaron hopping (SPH) model.
