Abstract The structural, electrical and magnetoresistance properties of Nd1-xPbxMnO3 with x = 0.1, 0.2, 0.3 & 0.4 have been investigated. All the samples were prepared through the modified sol-gel method. X-ray data were analyzed and found that the samples with x = 0.3 & 0.4 show the single-phase nature while the samples with x = 0.1 & 0.2 show the presence of minor extra NdMn2O5 phase with orthorhombic symmetry. Scanning electron microscopy (SEM) shows that the variation of grain growth was found with a change in the concentration of Pb. The temperature-dependent resistivity data shows the metal-insulator transition (TMI) with the higher values of Pb content (x = 0.3 & 0.4) and TMI shifts to higher temperatures with an applied magnetic field (2 T–8 T) excluding the x = 0.1 & 0.2 samples. Resistivity data were explored by the different suitable theoretical models below and above TMI. A very high value of MR (nearly 99.47%) was observed for x = 0.1 at 10 K under the applied magnetic field of 80 kOe. A sample with x = 0.3 also shows a higher MR of about 96.93% at 200 K with the applied magnetic field of 80 kOe.

中文翻译：

---

Pb 浓度对 Nd1-xPbxMnO3 结构和电传输特性的影响 (x=0.1, 0.2, 0.3 & 0.4)

摘要 研究了 x = 0.1、0.2、0.3 和 0.4 时 Nd1-xPbxMnO3 的结构、电学和磁阻特性。所有样品均采用改良的溶胶-凝胶法制备。对 X 射线数据进行分析，发现 x = 0.3 & 0.4 的样品显示单相性质，而 x = 0.1 & 0.2 的样品显示存在少量额外的 NdMn2O5 正交对称相。扫描电子显微镜 (SEM) 表明，随着 Pb 浓度的变化，发现晶粒生长的变化。与温度相关的电阻率数据显示金属-绝缘体转变 (TMI) 具有较高的 Pb 含量值 (x = 0.3 & 0.4)，并且 TMI 在外加磁场 (2 T–8 T) 下移至较高温度，不包括 x = 0.1 & 0.2 个样本。通过低于和高于 TMI 的不同合适的理论模型来探索电阻率数据。在 80 kOe 的外加磁场下，在 10 K 下观察到 x = 0.1 的非常高的 MR 值（接近 99.47%）。x = 0.3 的样品在 200 K 和 80 kOe 的外加磁场下也显示出约 96.93% 的更高 MR。