高质量镍基超晶格薄膜的制备及表征

自发现镍基超导薄膜之后, 镍基材料体系已成为当前人们的研究热点. 而在相关报道中, 普遍认为高质量的镍基超导前驱体薄膜的制备对其拓扑还原后超导电性的实现具有重要影响. 前期研究表明高质量的前驱体薄膜只生长在SrTiO3 衬底附近, 这与我们的实验结果一致. 为了可控制备高质量的镍基超导前驱体薄膜, 本文利用脉冲激光沉积(PLD) 技术在SrTiO3 (001) 衬底上生长不同厚度的可层选择性还原的SrTiO3 ]m/ Nd0 .8Sr0 .2 NiO3 ]n(STO)m/(NSNO)n ]超晶格薄膜. 采用反射高能电子衍射仪(RHEED) 及透射电子显微镜(STEM) 和 X 射线衍射(XRD) 技术对超晶格薄膜的结构进行原位检测及结构表征, 然后利用综合物性测量系统(PPMS) 测试薄膜的电磁输运性质. 结果表明, 超晶格薄膜的结构质量良好, 超晶格薄膜和高质量单层前驱体薄膜表现出类似的电阻和磁阻现象. 该研究为后续镍基超导薄膜的可重复制备提供了重要的参考.

Preparation and Characterization of High-Quality Nickel-Based Superlattice Thin Films

After the discovery of nickel-based superconducting thin films, the nickel-based materials system has become a current research hotspot. In related reports, itis generally believed that the preparation of high-quality nickel-based superconducting precursor films has an important impact on the realization of superconductivity after its topotactic reduction. Previous studies have shown that high-quality precursor films only grow near the SrTiO3 substrate, which is consistent with our experimental results. In order to controllably prepare high-quality nickel based superconducting precursor films, this study utilized pulsed laser deposition (PLD ) technology to grow selectively reduced (SrTiO3 )m/(Nd0 .8Sr0 .2 NiO3 )n (STO)m/(NSNO)n super lattice films of different thicknesses on STO (001) substrates. The structure of the superlattice film was detected and characterized using in-situ reflection high-energy electron diffraction (RHEED) , transmission electron microscopy (STEM ) , and X-ray diffraction (XRD) techniques, and then the transport properties of the films were measured using a Physical Property Measurement System (PPMS) . The results show that the structural quality of the super lattice film is good, and the super lattice film exhibits similar resistance and magneto-resistance phenomena to high-quality single-layer precursor films. This study provides important reference for the reproducible preparation of nickel-based superconducting films in the future.