Magnetic properties and impedance spectroscopic analysis in Pr0.7Ca0.3Mn0.95Fe0.05O3 perovskite ceramic
Autor: | N. Chniba-Boudjada, Muaffaq M. Nofal, Y. Moualhi, A. Cheikhrouhou, M. Gassoumi, A. Selmi, Kamel Khirouni, H. Rahmouni, Rafik M’nassri |
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Rok vydání: | 2020 |
Předmět: |
010302 applied physics
Phase transition Materials science Condensed matter physics Conductance Condensed Matter Physics Thermal conduction 01 natural sciences Power law Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Paramagnetism Ferromagnetism 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Grain boundary Electrical and Electronic Engineering Scaling |
Zdroj: | Journal of Materials Science: Materials in Electronics. 31:21046-21058 |
ISSN: | 1573-482X 0957-4522 |
Popis: | The orthorhombic Pr0.7Ca0.3Mn0.95Fe0.05O3 manganite is subject to magnetic and impedance spectroscopy measurements. This sample shows a paramagnetic to ferromagnetic phase transition at about 90 K. According to the Banerjee criterion, the nature of the magnetic transition is found to be of second order.The conductance spectra for Pr0.7Ca0.3Mn0.95Fe0.05O3 ceramic obey the power law variation for characterizing the hopping dynamics of charge carriers. The activation energies extracted from the dc conductance and hopping frequency show a positive correlation. Using the scaling approach, the conductance spectra are merged into a single master curve, confirming the validity of the time–temperature superposition principle. Equally, a strong deviation from the Summerfield scaling is observed. The random barrier model (RBM) is applied to correct this anomaly and a single master curve is constructed with a positive value of the scaling parameter α. Such parameter indicates a coulomb exchange between the interacting particles. Impedance results confirm the contribution of the resistive grain boundary on the electrical properties and the appearance of multiple electrical relaxation phenomena in Pr0.7Ca0.3Mn0.95Fe0.05O3 sample. From the evolution of the derivative ANC with temperature, we confirm the presence of various conduction mechanisms. The Nyquist plots show that the increase in temperature is followed by a decrease in the grain resistance (Rg) and the grain boundary resistance (Rgb) values. Such monotonic decrease confirms a predominant role of grain boundary contribution in governing the transport properties of Pr0.7Ca0.3Mn0.95Fe0.05O3 compound. |
Databáze: | OpenAIRE |
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