Eur. Phys. J. Plus (2019) 134: 304
https://doi.org/10.1140/epjp/i2019-12645-7

Regular Article

Sintering temperature effects on some physical properties of a Dy_0.5(Sr/Ca)_0.5MnO₃ system

¹ Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l’Environnement, Faculté des Sciences de Gabès cité Erriadh, Université de Gabès, 6079, Gabès, Tunisia
² Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax, B.P. 1171, 3000, Sfax, Tunisia
³ Physics Department, Faculty of Science, Aljouf University, Aljouf, Saudi Arabia
⁴ Unité de recherche Matériaux Avancés et Nanotechnologies (URMAN), Institut Supérieur des Sciences Appliquées et de Technologie de Kasserine, Université de Kairouan, BP 471, 1200, Kasserine, Tunisia

^* e-mail: rahmounihedi@yahoo.fr

Received: 27 October 2018
Accepted: 26 March 2019
Published online: 28 June 2019

Abstract

A Dy_0.5(Sr_0.95Ca_0.05)_0.5MnO₃ system has been prepared by the sol gel method and sintered at temperatures of 700 ^° C and 1350 ^° C for a similar period of time. Its electrical and dielectrical data as a function of frequency and temperature have been recorded by means of impedance spectroscopy. It is observed that the contribution of grain boundary to total resistance becomes dominant once increasing sintering temperature. The increase of sintering temperature increases the static dielectric constant by 25 times. Such interesting result is understood in the framework of many reasons including the presence of oxygen vacancies. Unlike sample sintered at 700 ^° C , the compound sintered at 1350 ^° C reveals two extra relaxation processes. Further, the sample sintered at 1350 ^° C possesses the higher value of the dielectric constant as well as a lower value of the loss tangent, which makes it a promising candidate for technological applications. For transport properties, the conduction process is found to be governed by the band gap model.