Abstract Controlled substitution of Praseodymium (Pr) in place of Lanthanum (La) was performed in La1.4-xPrxCa1.6Mn2O7 (x = 0.0, 0.1, 0.2, 0.3 and 0.4) to explore a possible enhancement in the magnetic and magnetocaloric properties of the material. The samples were produced following the solid-state reaction route. Rietveld refined XRD profiling was used that established the bilayer tetragonal structure (I4/mmm) of the Ruddlesden-Popper Phase in all compositions. Significant variations in the unit cell parameter were observed upon incorporation of Pr in place of La. Ferromagnetic to paramagnetic transitions were confirmed from the temperature dependent magnetization. Against the pristine sample, multiple folds increase was achieved in the values of magnetic entropy change ( Δ S M ) as well as the temperature averaged entropy change (TEC) with controlled Pr-substitution in the doped samples. Highest Δ S M and TEC (ΔTH-C = 10 K) values of 6.16 J kg −1K−1 and 8.329 J kg −1K−1 respectively were obtained in the x ≥ 0.3 samples at 2.5 T applied field. Our findings in this work suggest giant magnetocaloric effects in the Pr-doped samples and support the possibility of further tailoring these materials for applications in magnetic refrigeration technology.

中文翻译：

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Pr掺杂的La1.4-xPrxCa1.6Mn2O7双层锰酸盐中的大磁热效应

摘要 在 La1.4-xPrxCa1.6Mn2O7 (x = 0.0、0.1、0.2、0.3 和 0.4) 中进行了镨 (Pr) 代替镧 (La) 的受控取代，以探索可能增强材料。样品是按照固态反应路线生产的。使用 Rietveld 精制的 XRD 分析，在所有组合物中建立了 Ruddlesden-Popper 相的双层四方结构 (I4/mmm)。在加入 Pr 代替 La 后，观察到晶胞参数的显着变化。铁磁到顺磁的转变从温度相关的磁化强度中得到证实。相对于原始样本，掺杂样品中的磁熵变 (ΔSM) 值以及温度平均熵变 (TEC) 值都实现了多倍的增加，并具有受控的 Pr 取代。在 2.5 T 外加场的 x ≥ 0.3 样品中分别获得 6.16 J kg -1K-1 和 8.329 J kg -1K-1 的最高 Δ SM 和 TEC (ΔTH-C = 10 K) 值。我们在这项工作中的发现表明 Pr 掺杂的样品中存在巨大的磁热效应，并支持进一步定制这些材料以用于磁制冷技术的可能性。