Structural, magnetic, electrical and dielectric properties of Pr0.8Na0.2MnO3 manganite

I Ouni; H Ben Khlifa; R M'nassri; Muaffaq M Nofal; H Rahmouni; W Cheikhrouhou; N Chniba-Boudjada; K Khirouni; A Cheikhrouhou

doi:10.1039/c9ra05414f

Structural, magnetic, electrical and dielectric properties of Pr_0.8Na_0.2MnO₃ manganite

RSC Adv. 2019 Nov 1;9(61):35599-35607. doi: 10.1039/c9ra05414f. eCollection 2019 Oct 31.

Authors

I Ouni¹, H Ben Khlifa², R M'nassri¹, Muaffaq M Nofal³, H Rahmouni¹, W Cheikhrouhou², N Chniba-Boudjada⁴, K Khirouni⁵, A Cheikhrouhou²

Affiliations

¹ Unité de recherche Matériaux Avancés et Nanotechnologies, Institut Supérieur des Sciences Appliquées et de Technologie de Kasserine, Université de Kairouan BP 471 1200 Kasserine Tunisia rafik_mnassri@yahoo.fr.
² LT2S Lab, Digital Research Centre of Sfax SfaxTechnopark, Sakiet-Ezzit Tunisia.
³ Department of Mathematics and General Sciences, Prince Sultan University P. O. Box 66833 Riyadh 11586 Saudi Arabia.
⁴ Institut NEEL B. P. 166 38042 Grenoble Cedex 9 France.
⁵ Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l'Environnement, Faculté des Sciences de Gabès, Université de Gabès cité Erriadh 6079 Gabès Tunisia.

Abstract

The orthorhombic Pr_0.8Na_0.2MnO₃ ceramic was prepared in polycrystalline form by a Pechini sol-gel method and its structural, magnetic, electrical and dielectric properties were investigated experimentally. A structural study confirms that the sample is single phase. Magnetic measurements show that the sample is a charge ordered manganite. The sample undergoes two successive magnetic phase transitions with the variation of temperature: a charge ordering transition occurred at T _CO = 212 K followed by a paramagnetic (PM) to ferromagnetic (FM) transition around T _C = 115 K. From an electrical point of view, a saturation region was marked in the conductivity as a function of temperature σ(T) curves at a specific temperature. The dc-conductivity (σ _dc) reaches a maximum value at 240 K. The obtained results are in good agreement with the temperature dependence of the average normalized change (ANC). We found that the conduction mechanism was governed by small polaron hopping (SPH) in the high temperature region and by variable range hopping (VRH) in the low temperature region. Complex impedance analysis indicates the presence of a non-Debye relaxation phenomenon in the system. Also, the compound was modeled by an electrical equivalent circuit. Then, the contribution of the grain boundary in the transport properties was confirmed.