Investigation of magnetic and transport properties of PrCa(MnCo)O prepared by solid state process

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• 作者：M. Khelifi^a ; R. M&rsquo ; nassri^b ; A. Selmi^c ; H. Rahmouni^b ; ^{rahmounihedi@yahoo.fr" class="auth_mail" title="E-mail the corresponding author} ; K. Khirouni^a ; N. Chniba Boudjada^d ; A. Cheikhrouhou^c
• 关键词：Magnetocaloric properties ; Impedance analysis ; Hopping mechanism ; Landau analysis
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：423
• 期：Complete
• 页码：20-26
• 全文大小：1068 K

文摘

Magnetic, magnetocaloric and electrical properties in distorted orthorhombic system Pr_0.7Ca_0.3Mn_0.98Co_0.02O₃ has been studied. Complex impedance analysis confirms the contribution of grain boundary on the conduction process. The latter is dominated by thermally activated hopping mechanism. The sample exhibits two relaxations phenomena. Only one process persists at higher temperatures. Conductivity analysis indicates that the investigated compound exhibits a semiconductor behavior. The material reveals a dielectric transition and the experimental results are well fitted by Curie-Weiss law. The magnetic measurements show a clear paramagnetic–ferromagnetic transition with a large magnetic entropy change over a wide range of temperature. Furthermore, Banerjee's criteria and Landau theory of phase transitions are also studied to access magnetic ordering in the sample. A maximum magnetic entropy change increases from 0.5 to 2.18 J kg⁻¹ K⁻¹ when magnetic field rises from 1 T to 5 T. For the higher applied magnetic field, the material exhibits a high relative cooling power RCP=268.14 J/kg with a large temperature full-width at half maximum δ_TFWHM=123 K.