Abstract
The effect of Fe-doping at Mn-site on the structural and electrical properties of Nd
0.67
Ba
0.33
Mn
1−
x
Fe
x
O
3
(0 ≤ x ≤ 0.05) perovskites has been investigated. X-ray diffraction patterns show that the structural parameters change slightly due to the fact that the Fe
3+
ions replacing the Mn
3+
have similar ionic radius. The electrical properties of these samples have been investigated using complex impedance spectroscopy technique. a function of the frequency at different temperatures. When increasing the Fe-content, a decrease of dc conductivity was observed throughout the whole explored temperature range and the deduced activation energy values are found to increase from 128 meV for x = 0 to 166 meV for x = 0.05. The curves of the imaginary part of impedance (Z″) show the presence of relaxation phenomenon in our samples. The complex impedance spectra show semicircle arcs at different temperatures and an equivalent circuit of the type of R
g
+ (R
gb
//C
gb
) has been proposed to explain the impedance results.