陈斌杰^1，， 孙岩^2，， 杨楠^2，， 钟妮^2，， 张媛媛^2，， 白伟^2，， 孙琳^2，， 唐晓东^2，， 杨平雄^2，， 向平华^1，*， 段纯刚^2，

（  1、华东师范大学，电子工程系，极化材料与器件教育部重点实验室，上海 200241；       2、Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241；  ）

摘要： 本文运用脉冲激光沉积方法，在多种氧分压（PO2）条件下，于（001）取向的铝酸镧（LaAlO3）衬底上制备了含氧空位的镍酸钐（SmNiO3-δ）外延薄膜。实验结果表明，随着氧分压从26Pa变化到0.5Pa，镍酸钐薄膜的金属-绝缘体相变温度（TMI）从350K逐渐向85K移动。TMI的降低可归因于面外的Ni-O-Ni键角随PO2降低而增大。同时，在PO2 > 3 Pa的条件下，可以在200K附近的绝缘相中进一步观测到电阻率的异常变化，这表明镍晶格的反铁磁序的发生。结合以上结果，本文绘制了含氧空位的镍酸钐薄膜的电子相图。
关键词： 物理电子学；镍酸盐薄膜；电子输运；金属-绝缘体相变；氧空位

CHEN Binjie， SUN Yan， YANG Nan， ZHONG Ni， ZHANG Yuanyuan， BAI Wei， SUN Lin， TANG Xiaodong， YANG Pinxiong， XIANG Pinghua^*， DUAN Chungang

（  Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241；  ）

Abstract： Epitaxial SmNiO3-δ thin films were fabricated under various oxygen partial pressures (PO2) on (001)-oriented LaAlO3 substrates by pulsed laser deposition method. Continuous control of the metal-insulator transition temperature (TMI) from 350 K to 85 K has been achieved by varying PO2 from 26 Pa to 0.5 Pa. The reduction of TMI can be attributed to the straightening out of the out-of-plane Ni-O-Ni bond angle due to the elongation of unit cell volume with decrease of PO2. When PO2 > 3 Pa, the resistivity anomalies around 200 K are observed in the insulating phase of strained SmNiO3-δ films, suggesting the onset of antiferromagnetic ordering of the Ni sublattices. Based on the results of the transport measurements, an electronic phase diagram of the oxygen deficient SmNiO3-δ films has been established in this work.

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