Abstract
We have investigated the structural, magnetic, and electrical transport properties of a series of ABO
3
-type perovskite compounds, La
0.67
Sr
0.33
Mn
1−
x
V
x
O
3
(0≤
x
≤0.15). The samples were characterized by X-ray diffraction and data were analyzed using Rietveld refinement technique, it has been concluded that these materials have the rhombohedral structure with
space group. The magnetization and resistivity measurements versus temperature proved that all our samples exhibit a ferromagnetic to paramagnetic transition and a metallic to semiconductor one when the temperature increases. Both the Curie temperature
T
C
and the resistivity transition temperature
T
P
of the composites decrease, while the resistance increases as the V content increases. It has been concluded that the electrical conduction mechanism in the metallic regime at low temperatures (
T
<
T
P
) can be explained on the basis of grain boundary effects and the single electron-magnon scattering process. Resistivity data were well fitted with the relation
ρ
=
ρ
0
+
ρ
2
T
2
+
ρ
4.5
T
4.5
, whereas the adiabatic Small Polaron Hopping (SPH) and Variable Range Hopping (VRH) models are found to fit well in the paramagnetic semiconducting regime at the high temperature (
T
>
T
P
).