Nanocomposites consist of ZnO and La_0.3Ca_0.7MnO₃ (LCMO) nanoparticles, prepared by cost effective sol–gel method, have been studied for their transport and magnetoresistance (MR) behaviors. Different ZnO nanoparticles contents (weight ratio) were mixed with LCMO nanostructured manganite to understand the possible interactions between ZnO and LCMO nanoparticles. X–ray diffraction (XRD) measurement was performed for all composites and structural quality was verified by performing Rietveld refinements. Variation in an average crystallite size for LCMO and ZnO nanoparticles in different composites has been discussed. Temperature dependent resistivity measurements under different applied magnetic fields suggest the semiconducting nature of all nanocomposites under all applied magnetic fields. Mott type variable range hopping (VRH) mechanism has been employed to understand the dependence of charge carrier localization in LCMO nanostructured manganite lattice on the applied magnetic field and ZnO nanoparticles content within the nanocomposites. Observed MR behavior has been understood under the influence of temperature and ZnO nanoparticles content in the context of spin polarized tunneling (SPT) and magnetic field induced improved conduction across the manganite lattice. Grain and grain boundary contributions to the MR behavior have been explained by using theoretical model fits to obtained MR data at different temperatures for all studied LCMO:ZnO nanocomposites. Magnetic nature of studied LCMO:ZnO nanocomposites has been understood by performing zero field cooled (ZFC) and field cooled (FC) measurement protocols based magnetization and magnetic isotherms measurements that confirm the coexisting magnetic phase in all studied nanocomposites. Magnetic nature has been understood on the basis of weakening of zener double exchange (ZDE) mechanism within the magnetic lattice of LCMO manganite and magnetic contribution from the free charge carriers within the ZnO clusters.

纳米复合材料由 ZnO 和 La _0.3 Ca _0.7 MnO _{3 组成}(LCMO) 纳米粒子，通过具有成本效益的溶胶-凝胶方法制备，已经研究了它们的传输和磁阻 (MR) 行为。将不同含量的 ZnO 纳米颗粒（重量比）与 LCMO 纳米结构锰矿混合，以了解 ZnO 和 LCMO 纳米颗粒之间可能的相互作用。对所有复合材料进行 X 射线衍射 (XRD) 测量，并通过执行 Rietveld 改进来验证结构质量。已经讨论了不同复合材料中 LCMO 和 ZnO 纳米颗粒的平均微晶尺寸的变化。在不同外加磁场下的温度相关电阻率测量表明所有纳米复合材料在所有外加磁场下都具有半导体性质。Mott 型可变范围跳跃 (VRH) 机制已被用于了解 LCMO 纳米结构锰矿晶格中电荷载流子定位对施加的磁场和纳米复合材料中 ZnO 纳米颗粒含量的依赖性。在温度和 ZnO 纳米粒子含量的影响下，在自旋极化隧道 (SPT) 和磁场诱导改善的锰矿晶格传导的背景下，观察到的 MR 行为已经被理解。通过使用理论模型拟合在所有研究的 LCMO:ZnO 纳米复合材料在不同温度下获得的 MR 数据，已经解释了晶粒和晶界对 MR 行为的贡献。所研究的 LCMO 的磁性：通过执行基于磁化和磁等温线测量的零场冷却 (ZFC) 和场冷却 (FC) 测量协议，已了解 ZnO 纳米复合材料，这些测量方案证实了所有研究的纳米复合材料中的共存磁相。基于 LCMO 锰矿磁晶格内齐纳双交换 (ZDE) 机制的减弱和 ZnO 簇内自由电荷载流子的磁性贡献，已经理解了磁性。