Saadaoui F, M Nofal Muaffaq, M'nassri R, Koubaa M, Chniba-Boudjada N, Cheikhrouhou A
Unité de Recherche Matériaux Avancés et Nanotechnologies (URMAN), Institut Supérieur des Sciences Appliquées et de Technologie de Kasserine, Kairouan University BP 471 Kasserine 1200 Tunisia
Department of Mathematics and General Sciences, Prince Sultan University P. O. Box 66833 Riyadh 11586 Saudi Arabia.
RSC Adv. 2019 Aug 12;9(43):25064-25074. doi: 10.1039/c9ra04141a. eCollection 2019 Aug 8.
In this work, we present the results of the magnetic, critical, and magnetocaloric properties of the rhombohedral-structured LaBiSrCoO cobaltite. Based on the modified Arrott plot, Kouvel-Fisher, and critical isotherm analyses, we obtained the values of critical exponents (, , and ) as well as Curie temperature ( ) for the investigated compound. These components were consistent with their corresponding values and they were validated by the Widom scaling law and scaling theory. The obtained critical exponents were close to the theoretical prediction of the mean-field model values, revealing the characteristic of long-range ferromagnetic interactions. The magnetic entropy, heat capacity, and local exponent (, ) of the LaBiSrCoO compound collapsed to a single universal curve, confirming its universal behaviour. The estimated spontaneous magnetization value extracted through the analysis of the magnetic entropy change was consistent with that deduced through the classical extrapolation of the Arrott curves. Thus, the magnetic entropy change is a valid and useful approach to estimate the spontaneous magnetization of LaBiSrCoO.
在这项工作中，我们展示了菱面体结构的镧铋锶钴酸盐的磁性、临界和磁热性质的研究结果。基于修正的阿罗特图、库维尔-费舍尔分析和临界等温线分析，我们获得了所研究化合物的临界指数（α、β和γ）以及居里温度（Tc）的值。这些分量与它们相应的值一致，并通过维登标度律和标度理论得到验证。所获得的临界指数接近平均场模型值的理论预测，揭示了长程铁磁相互作用的特征。镧铋锶钴酸盐化合物的磁熵、热容和局域指数（α、γ）汇聚到一条单一的通用曲线上，证实了其通用行为。通过磁熵变分析提取的估计自发磁化值与通过阿罗特曲线的经典外推法推导的值一致。因此，磁熵变是估计镧铋锶钴酸盐自发磁化的一种有效且有用的方法。
