Abstract Thin films of layered perovskites Sr 1.5 RE 0.5 CoO 4 (RE = La, Gd) were grown on MgO (0 0 1) substrate using pulsed laser ablation method. Structural, electrical and magnetic properties of single phase oriented films were studied. Films reveal semiconducting behavior in the entire measured temperature range. The films show thermally activated behavior at high temperature regime, with a higher value of activation energy for SGCO than that for SLCO. The low temperature behavior is well fitted with 3D-variable range hopping mechanism. Both films showed negative magneto-resistance measured in temperature range of 10–200 K. The value of MR is large for SGCO film as compared to its bulk counterpart as well as SLCO film, suggesting its high potential in the spintronics applications. A pinch-shaped M−H behaviour as observed in both the films, suggests the presence of two-magnetic phases. Occurrence of pinch-shape behaviour is although in line with that of SLCO bulk counterpart, interestingly, it was absent in SGCO polycrystalline powder. It suggests major role of film growth kinetics in modifying the magnetic properties in cobaltites.

中文翻译：

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稀土掺杂层状钴酸钙薄膜的电学和磁学特性研究

摘要 使用脉冲激光烧蚀方法在 MgO (0 0 1) 衬底上生长层状钙钛矿 Sr 1.5 RE 0.5 CoO 4 (RE = La, Gd) 薄膜。研究了单相取向薄膜的结构、电学和磁学特性。薄膜在整个测量温度范围内显示出半导体行为。薄膜在高温状态下表现出热活化行为，SGCO 的活化能值高于 SLCO。低温行为非常适合 3D 可变范围跳跃机制。两种薄膜都显示出在 10-200 K 温度范围内测量的负磁阻。 与其体对应物以及 SLCO 薄膜相比，SGCO 薄膜的 MR 值较大，表明其在自旋电子学应用中具有很高的潜力。在两种薄膜中观察到的捏形 M-H 行为，表明存在两个磁性相。尽管与 SLCO 本体对应物一致，但捏形行为的发生在 SGCO 多晶粉末中不存在。这表明薄膜生长动力学在改变钴酸盐中的磁性方面的主要作用。