In the present communication, structural, microstructural and electrical properties of La_0.5Nd_0.2Ca_0.3MnO₃ (LNCMO) and La_0.5Nd_0.2Sr_0.3MnO₃ (LNSMO) mixed valent manganite films, grown on single crystalline (0001) Al₂O₃ (ALO) substrates using pulsed laser deposition (PLD) technique, have been studied. After deposition, one set of LNCMO and LNSMO films were annealed in oxygen environment at 500 °C (hereafter referred as LNC–A & LNS–A, respectively) and compared their properties with other set of PLD as–grown LNCMO and LNSMO films (hereafter referred as LNC and LNS, respectively). Single crystalline growth of LNCMO films and polycrystalline growth of LNSMO films have been identified through X–ray diffraction (XRD) measurement. Atomic force microscopy (AFM) measurement for morphological studies indicates that divalent dopant and oxygen annealing process play an important role in governing the grain growth and surface nature of the studied films. A decrease in the value of resistance (R) and impedance (Z) with increase in frequency under the applied magnetic field (H = 1 T) has been observed for all the studied films. For LNC & LNC–A films, reactance is found to decrease monotonically with increase in frequency throughout its range studied while for LNS and LNS–A films, reactance initially increases followed by reduction in its value with increase in frequency under 0 and 1 T magnetic field has been observed. The variation in MR for LNS and LNS–A films has been discussed in the context of charge transport mechanism and Lorentz force. Further, to discuss the role of grain and grain boundaries, nyquist plots and their suitable fits under zero and 1 T external magnetic field have been investigated for all the studied mixed valent manganite films. Important role of phase separation scenario in studied manganite films has been discussed in detail based on magnetization measurement. Double magnetic phase transition and fluctuations in derivative of magnetization have been ascribed to the phase separation scenario of LNCMO / ALO and LNSMO / ALO mixed valent manganite thin films.

在目前的通讯中，La _0.5 Nd _0.2 Ca _0.3 MnO ₃ (LNCMO) 和 La _0.5 Nd _0.2 Sr _0.3 MnO ₃ (LNSMO) 混合价锰酸盐薄膜的结构、微观结构和电性能，生长在单晶(0001) Al ₂ O 上₃已经研究了使用脉冲激光沉积 (PLD) 技术的 (ALO) 基板。沉积后，一组 LNCMO 和 LNSMO 薄膜在 500 °C 的氧气环境中退火（以下分别称为 LNC-A 和 LNS-A），并将它们的性能与另一组 PLD 生长的 LNCMO 和 LNSMO 薄膜进行比较（以下分别称为 LNC 和 LNS）。LNCMO 薄膜的单晶生长和 LNSMO 薄膜的多晶生长已通过 X 射线衍射 (XRD) 测量确定。用于形态学研究的原子力显微镜 (AFM) 测量表明，二价掺杂剂和氧退火过程在控制所研究薄膜的晶粒生长和表面性质方面起着重要作用。对于所有研究的薄膜，在施加的磁场 (H = 1 T) 下，电阻 (R) 和阻抗 (Z) 的值随着频率的增加而减小。对于 LNC 和 LNC-A 薄膜，发现电抗在整个研究范围内随着频率的增加而单调降低，而对于 LNS 和 LNS-A 薄膜，电抗最初增加，然后在 0 和 1 T 磁下随着频率的增加而降低其值场进行了观察。LNS 和 LNS-A 薄膜的 MR 变化已经在电荷传输机制和洛伦兹力的背景下进行了讨论。此外，为了讨论晶界和晶界的作用，已经研究了所有研究的混合价锰酸盐薄膜在零和 1 T 外部磁场下的奈奎斯特图及其合适的拟合。已经基于磁化测量详细讨论了相分离场景在所研究的锰矿薄膜中的重要作用。双磁相变和磁化导数的波动归因于 LNCMO / ALO 和 LNSMO / ALO 混合价锰酸盐薄膜的相分离情况。