Cayado Pablo, Rijckaert Hannes, Bruneel Els, Erbe Manuela, Hänisch Jens, Van Driessche Isabel, Holzapfel Bernhard
Karlsruhe Institute of Technology (KIT), Institute for Technical Physics (ITEP), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
Department of Chemistry, Ghent University, SCRiPTS, Krijgslaan, 281-S3, 9000, Ghent, Belgium.
Sci Rep. 2020 Nov 10;10(1):19469. doi: 10.1038/s41598-020-75587-4.
For the first time, GdBaCuO nanocomposites were prepared by chemical solution deposition following the ex-situ approach. In particular, ~ 220 nm GdBaCuO-HfO (GdBCO-HfO) nanocomposite films were fabricated starting from a colloidal solution of 5 mol% HfO nanoparticles. Hereby, one of the main challenges is to avoid the accumulation of the nanoparticles at the substrate interface during the pyrolysis, which would later prevent the epitaxial nucleation of the GdBCO grains. Therefore, the effect of pyrolysis processing parameters such as heating ramp and temperature on the homogeneity of the nanoparticle distribution has been investigated. By increasing the heating ramp to 300 °C/h and decreasing the final temperature to 300 °C, a more homogenous nanoparticle distribution was achieved. This translates into improved superconducting properties of the grown films reaching critical temperatures (T) of 94.5 K and self-field critical current densities ([Formula: see text]) at 77 K of 2.1 MA/cm with respect to films pyrolyzed at higher temperatures or lower heating ramps.
首次采用非原位方法通过化学溶液沉积制备了钆钡铜氧（GdBaCuO）纳米复合材料。具体而言，从5 mol% 氧化铪（HfO）纳米颗粒的胶体溶液开始制备了约220纳米的钆钡铜氧 - 氧化铪（GdBCO - HfO）纳米复合薄膜。在此过程中，一个主要挑战是避免在热解过程中纳米颗粒在衬底界面处聚集，这随后会阻碍GdBCO晶粒的外延成核。因此，研究了热解工艺参数（如升温速率和温度）对纳米颗粒分布均匀性的影响。通过将升温速率提高到300℃/小时并将最终温度降低到300℃，实现了更均匀的纳米颗粒分布。相对于在更高温度或更低升温速率下热解的薄膜，这转化为生长薄膜的超导性能得到改善，临界温度（T）达到94.5 K，在77 K时的自场临界电流密度（[公式：见原文]）为2.1 MA/cm² 。
