Conventional solid-state reaction technique was used to prepare the studied samples La_0.55Ca_xSr_0.45−xMnO₃ (x = 0.0, 0.1, 0.2). Their structural and magnetic properties have been investigated to find the effect of calcium doping on the D.C. and A.C. magnetic properties of the compounds. Room temperature XRD investigations confirm rhombohedral structure with space group R-3c for all the samples. Lattice parameter is found to decrease with increase in Ca(x) content. Microstructure was examined from the images taken by Scanning Electron Microscopy (SEM) and chemical compositions were determined by an energy dispersive X-ray diffractometer (EDX). The zero-field cooled (ZFC) and field cooled (FC) DC magnetization measurements reveal paramagnetic (PM) to ferromagnetic (FM) transition in them upon cooling through their Curie temperature (T_C). But the FM state coexists with the residual canted anti-ferromagnetic state rather than a pure FM state in the samples. The T_C values are dependent on Ca(x) content of the samples. Moreover, XRD analysis and EDX data reveals the presence of Mn deficiency in the studied samples. Presence of minor secondary Mn₃O₄ phase creates this deficiency resulting a significant decrease in T_C and strongly influences the magnetic properties. The values of A.C. permeability (μʹ) also depend on Ca(x) content as well as grain size that can be explained by Globus equation. However, μʹ values of the samples remain almost constant over a wide range of frequency which indicates the compositional stability of the perovskites. The magnetic modulus demonstrates the dynamics of their A.C. permeability by screening out the stray/any other effects in them. The Nyquist plots of magnetic modulus of the samples show the type of their magnetic relaxation.

采用传统的固相反应技术制备了研究样品La _0.55 Ca _x Sr _0.45-x MnO ₃（x = 0.0、0.1、0.2）。已经研究了它们的结构和磁性，以发现钙掺杂对化合物的直流和交流磁性的影响。室温XRD研究证实了所有样品的R-3c空间群为菱形结构。发现晶格参数随Ca（x）含量的增加而降低。从通过扫描电子显微镜（SEM）拍摄的图像检查微观结构，并通过能量色散X射线衍射仪（EDX）确定化学组成。零场冷却（ZFC）和场冷却（FC）直流磁化测量显示，在通过居里温度（T _C）冷却后，其中的顺磁（PM）到铁磁（FM）转变）。但是，样品中的FM状态与残留的倾斜反铁磁状态共存，而不是纯FM状态。T _C值取决于样品的Ca（x）含量。此外，XRD分析和EDX数据揭示了所研究样品中Mn的缺乏。存在次要的Mn ₃ O ₄次相会导致这种缺陷，从而导致T _C显着降低并强烈影响磁性能。AC磁导率（μl）的值还取决于Ca（x）含量以及可由Globus方程解释的晶粒尺寸。但是，样品的μl值在很宽的频率范围内几乎保持恒定，这表明钙钛矿的组成稳定性。磁模量通过筛选杂散/其他任何影响来证明其交流磁导率的动态。样品的磁模量的奈奎斯特图显示了其磁弛豫的类型。