Abstract
Polycrystalline Nd0.5Ba0.5FeO3 (NBFO) perovskite was prepared with sol-gel method, calcined at a temperature of 900 degrees C. Here, we study the influence of the Barium ion Ba(2+)introduced in the Nd site on the structural, electrical, dielectric and thermodynamic properties of our NBFO sample. The electrical conductivity obeying the Jonscher's power law indicates that the prepared material shows a semiconducting behavior, and that the conduction process is presented by charge carriers performing an abrupt translational motion (NSPT model). The behavior of dielectric constants such as permittivity and loss coefficient has been interpreted based on the Maxwell-Wagner's theory of interfacial polarization. The curves of imaginary parts of impedance (ZMODIFIER LETTER PRIMEMODIFIER LETTER PRIME) and modulus (MMODIFIER LETTER PRIMEMODIFIER LETTER PRIME) show a dielectric relaxation phenomenon in the sample with activation energy near to that determined from the dc conductivity study. TheNyquist diagram (ZMODIFIER LETTER PRIMEMODIFIER LETTER PRIME vs. ZMODIFIER LETTER PRIME) tells us that the grain resistance (R-g) and the grain boundary resistance (R-gb) decrease monotonically with an increase in temperature. The latter result confirms that the charge carrier motion is related to the abrupt jump displacement. This result indicates that the transport mechanism for NBFO compound is governed by the grain boundaries effect. In addition, thermodynamic factors including enthalpy Delta H, entropy Delta S, and free energy of activation Delta F were identified.