Double Jonscher response and contribution of multiple mechanisms in electrical conductivity processes of Fe-PrCaMnO ceramic

• Published in: Ceramics international 2020-02, Vol.46 (2), p.1601-1608
• Main Authors: Moualhi, Y., Nofal, Muaffaq M., M'nassri, R., Rahmouni, H., Selmi, A., Gassoumi, M., Khirouni, K., Cheikrouhou, A.
• Format: Article
• Language: English
• Subjects: Double jonscher response; Electrical conductivity; Impedance spectroscopy; ISSAT kasserine; Praseodymium manganite; URMAN
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2019.09.131

In this work, the ceramic Fe-PrCaMnO manganite was synthesized by means of standard high-temperature solid-state reaction technique. X-ray diffraction of Pr0.7Ca0·3Mn0·95Fe0·05O3 was indexed to a perovskite single phase. Then, all reflections appearing in the diffraction patterns were indexed and assigned to the orthorhombic Pnma space group. Electrical investigations show that the sample presents two dissimilar behaviours. A semiconductor character was observed at low temperature region [80K–250K]. Then, a metallic behaviour was detected beyond T = 250K. Then, a saturation region was marked. At low temperature region, ac-conductivity analysis shows the coexistence of two frequency dependent conduction mechanisms. The Correlated Barrier Hopping (CBH) mechanism was observed at the intermediate frequency range and a Non-Small Polaron Tunneling (NSPT) one was detected at high frequency side. In the temperature range [140K–170K], a signature of a Quantum Mechanical Tunneling (QMT) conduction mechanism was noticed. Then, beyond T = 170 K, the CBH mechanism dominated the transport properties. A double Jonscher response and the contribution of multiple mechanisms in electrical conductivity processes of Fe-PrCaMnO system were confirmed. Then, the frequency dependence of ac-conductance has been clarified by several conduction Models (CBH, NSPT and QMT).