Dhahri Ahmed, Laifi J, Gouadria Soumaya, Elhadi M, Dhahri E, Hlil E K
Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Université de Sfax BP 1171 3000 Tunisia
Department of Physics, College of Science and Humanities - Dawadmi, Shaqra University Riyadh Saudi Arabia.
RSC Adv. 2022 Feb 1;12(7):3935-3947. doi: 10.1039/d1ra07059b. eCollection 2022 Jan 28.
We present a detailed study on the physical properties of LaBaSrMn Ni O samples ( = 0.00, 0.05 and 0.1). The ceramics were fabricated using the sol-gel route. Structural refinement, employing the Rietveld method, disclosed a rhombohedral 3̄ phase. The magnetization temperature plots show a paramagnetic-ferromagnetic (PM-FM) transition phase at the (Curie temperature), which decreases from 354 K to 301 K. From the Arrott diagrams /, we can conclude the phase transition is of the second order. Based on measurements of the isothermal magnetization around , the magnetocaloric effects (MCEs) have been calculated. The entropy maximum change (-Δ ) values are 7.40 J kg K, 5.6 J kg K and 4.48 J kg K, whereas the relative cooling power (RCP) values are 232 J kg, 230 J kg and 156 J kg for = 0.00, 0.05 and 0.10, respectively, under an external field ( ) of 5 T. Through these results, the LaBaSrMn Ni O (0 ≤ ≤ 0.1) samples can be suggested for use in magnetic refrigeration technology above room temperature. The electrical resistivity () temperature plots exhibit a transition from metallic behavior to semiconductor behavior in the vicinity of . The adiabatic small polaron hopping (ASPH) model is applied in the PM-semiconducting part ( > ). Throughout the temperature range, is adjusted by the percolation model. This model is based on the phase segregation of FM-metal clusters and PM-insulating regions.
我们对LaBaSrMnNiO样品（= 0.00、0.05和0.1）的物理性质进行了详细研究。这些陶瓷采用溶胶 - 凝胶法制备。利用Rietveld方法进行结构精修，揭示出菱面体3̄相。磁化强度 - 温度曲线在（居里温度）处显示出顺磁 - 铁磁（PM - FM）转变相，该温度从354 K降至301 K。从阿罗特图 / 中，我们可以得出相变是二级相变。基于在 附近的等温磁化强度测量，计算了磁热效应（MCE）。在5 T的外磁场（ ）下，对于 = 0.00、0.05和0.10，熵最大变化（-Δ ）值分别为7.40 J kg K、5.6 J kg K和4.48 J kg K，而相对制冷功率（RCP）值分别为232 J kg、230 J kg和156 J kg。通过这些结果，LaBaSrMnNiO（0 ≤ ≤ 0.1）样品可被建议用于室温以上的磁制冷技术。电阻率（） - 温度曲线在 附近呈现出从金属行为到半导体行为的转变。在顺磁 - 半导体部分（ > ）应用了绝热小极化子跳跃（ASPH）模型。在整个温度范围内， 通过渗流模型进行调整。该模型基于铁磁 - 金属簇和顺磁 - 绝缘区域的相分离。
