论文标题
A轴YBA2CU3O7-X/PRBA2CU3O7-X/YBA2CU3O7-X带子纳光度RMS粗糙度的Trilayers
a-axis YBa2Cu3O7-x/PrBa2Cu3O7-x/YBa2Cu3O7-x trilayers with subnanometer rms roughness
论文作者
论文摘要
我们演示了A轴YBA2CU3O7-X/PRBA2CU3O7-X/YBA2CU3O7-X TRILAYERS（100）LAALO3底物，具有改善的界面光滑度。这些三层由臭氧辅助分子梁外延合成。 PRBA2CU3O7-X层的厚度在8 nm处保持恒定，Yba2Cu3O7-X层的厚度从24 nm到100 nm变化。 X射线衍射测量结果显示所有三层均具有> 95％的A轴含量。最薄的三层层的RMS粗糙度<0.7 nm，这种粗糙度随Yba2Cu3O7-X层的厚度而增加。 YBA2CU3O7-X层的厚度也会影响运输特性：虽然所有样品在85 K处和高于85 K以上的超导过渡的发作时，较薄的样品显示较宽的过渡宽度ΔTC。高分辨率扫描透射电子显微镜揭示了连贯且化学锐利的界面，并且该生长始于立方（Y，BA）CuO3-X钙钛矿相位，该相变为面向A轴的YBA2CU3O77-X，因为底物温度已升高。
We demonstrate a-axis YBa2Cu3O7-x/PrBa2Cu3O7-x/YBa2Cu3O7-x trilayers grown on (100) LaAlO3 substrates with improved interface smoothness. The trilayers are synthesized by ozone-assisted molecular-beam epitaxy. The thickness of the PrBa2Cu3O7-x layer is held constant at 8 nm and the thickness of the YBa2Cu3O7-x layers is varied from 24 nm to 100 nm. X-ray diffraction measurements show all trilayers to have >95% a-axis content. The rms roughness of the thinnest trilayer is < 0.7 nm and this roughness increases with the thickness of the YBa2Cu3O7-x layers. The thickness of the YBa2Cu3O7-x layers also affects the transport properties: while all samples exhibit an onset of the superconducting transition at and above 85 K, the thinner samples show wider transition widths, ΔTc. High-resolution scanning transmission electron microscopy reveals coherent and chemically sharp interfaces, and that growth begins with a cubic (Y,Ba)CuO3-x perovskite phase that transforms into a-axis oriented YBa2Cu3O7-x as the substrate temperature is ramped up.
