MOCVD-derived GdYBCO tapes with smooth surface and low R-s based on a new self-heating technology
MOCVD-derived GdYBCO tapes with smooth surface and low R-s based on a new self-heating technology
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基于新型自加热技术的 MOCVD 衍生 GdYBCO 带，具有光滑表面和低 R-s
DOI：
10.1016/j.ceramint.2018.03.234
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发表时间：
2018
影响因子：
5.2
通讯作者：
Li Yanrong
中科院分区：
文献类型：
--
作者：
Zhao Ruipeng;Ma Yinchang;Liu Qing;Zhang Fei;Xia Yudong;Tang Hao;Lu Yuming;Cai Chuanbing;Tao Bowan;Li Yanrong
采用金属有机化学气相沉积（MOCVD）方法在LaMnO3/ homo外延- mgo /离子束辅助沉积- mgo /溶液沉积-平面化- y2o3缓冲哈氏合金带上制备了GdYBCO薄膜。采用一种简单的自加热技术，在哈氏合金金属带上施加加热电流（Ih）后，利用焦耳效应加热基片。通过改变fihandrc值，系统地研究了衬底温度和前驱体中（Gd， Y）/Ba比（rc）对GdYBCO薄膜双轴织构、表面形貌和超导性能的影响。利用扫描电镜、能谱仪和x射线衍射系统对衬底表面形成的针状生长物进行了表征。结果表明，高强度会导致针状生长物的形成。因此，我需要掌握控制GdYBCO薄膜表面针状生长的关键工艺参数。采用MOCVD法制备了300纳米厚的GdYBCO薄膜。在温度为27.0 A，温度为0.6时，GdYBCO薄膜表面非常光滑致密，可以为GdYBCO薄膜的多次沉积提供良好的模板。制备的300 nm厚GdYBCO薄膜的临界电流密度为4.4 MA/cm2(77 K, 0 T)，这主要归因于良好的双轴织构和合适的薄膜成分。此外，GdYBCO薄膜的微波表面电阻（77 K, 10 GHz）仅为0.581 mΩ。
The metal organic chemical vapor deposition (MOCVD) method was used to prepare GdYBCO films on LaMnO3/ homo epitaxial-MgO/ ion-beam-assisted-deposition-MgO/ solution-deposition-planarization-Y2O3buffered Hastelloy tapes. By adopting a simple self-heating technique, the substrates were heated by the joule effect after applying a heating current (Ih) through Hastelloy metal tapes. The effects of substrate temperature and (Gd, Y)/Ba ratio (rc) in the precursor on the biaxial texture, surface morphology and superconducting performance of GdYBCO films were systematically investigated by varying the values ofIhandrc. Needle-like outgrowths formed on the substrate surface were characterized using a scanning electron microscope, energy dispersive spectrometer and X-ray diffraction system. The results show that a highIhorrcleads to the formation of needle-like outgrowths. Therefore,Ihandrcare crucial process parameters that control the growth of needle-like outgrowths on the surface of GdYBCO films. Three hundred nanometer thick GdYBCO films were prepared at differentIhandrcby the MOCVD process. At anIhof 27.0 A and anrcof 0.6, the surface of the GdYBCO film was very smooth and dense, which can provide a good template for multiple depositions of GdYBCO films. The critical current density of the deposited 300 nm-thick GdYBCO film was 4.4 MA/cm2(77 K, 0 T), which is attributed to good biaxial texture and appropriate film composition. Furthermore, the microwave surface resistance (77 K, 10 GHz) of the GdYBCO film was merely 0.581 mΩ.