In this research paper, our central focus is upon structural, optic, magnetic, magnetocaloric, and critical phenomena of La_0.57Nd_0.1Sr_0.18Ag_0.15MnO₃ (LNSMAO) compound. This compound is crystallized in the rhombohedric system, with a \(R\mathop 3\limits^{ - } c\) space group. The band gap energy of this powder was 2.5 eV. Therefore, the LNSAMO sample proved to be not only a photocatalysis material but also a photovoltaic application. The FTIR spectra confirmed the formation of the structure of orthorhombic perovskite. The second-order transition of the magnetic phase in the LNSMAO sample was also reported by the positive slopes of the Arrott plot. Beneath 5 T, the values of magnetic entropy change and relative cooling power, respectively, amounted to about 5.08 J kg⁻¹ K⁻¹ and 146.7 J/Kg. In perspective, this sample stands for an agreeable candidate for magnetic refrigeration. By analyzing the dependence on the field of the magnetic entropy change (ΔS_M) data as well as the relative cooling power (RCP), it was possible to assess the values of the critical exponents. Moreover, the critical exponents of LNSMAO compound were estimated based on multiple techniques like Kouvel-Fisher (KF), modified Arrott plot (MAP) method, and critical isotherm analysis (CIA). The reliability of these critical behaviors was verified by the Widom scaling relation and the universal scaling hypothesis. Our results demonstrate an excellent correlation between magnetocaloric effect (MCE) properties in manganese systems and critical behavior.

在这篇研究论文中，我们的重点是La _0.57 Nd _0.1 Sr _0.18 Ag _0.15 MnO ₃（LNSMAO）化合物的结构，光学，磁性，磁热和临界现象。该化合物在菱面体系统中以\（R \ mathop 3 \ limits ^ {-} c \）结晶。空间群。该粉末的带隙能为2.5eV。因此，LNSAMO样品不仅被证明是光催化材料，而且还是光伏应用。FTIR光谱证实了正交晶钙钛矿结构的形成。LNSMAO样品中磁性相的第二阶跃迁也通过Arrott图的正斜率报告。在5 T以下，磁熵变和相对冷却功率的值分别约为5.08 J kg ^-1  K ^-1和146.7 J / Kg。从角度来看，此样本代表磁制冷的合适候选者。通过分析在磁熵变的场的依赖（ΔS_中号）数据以及相对冷却功率（RCP），就可以评估关键指数的值。此外，LNSMAO化合物的临界指数是根据多种技术估算的，例如Kouvel-Fisher（KF），改良的Arrott图（MAP）方法和临界等温线分析（CIA）。这些关键行为的可靠性通过Widom比例关系和通用比例假设进行了验证。我们的结果表明，锰系统中的磁热效应（MCE）特性与临界行为之间具有极好的相关性。