抄録
We have reported high-Jc Sm1+xBa2-xCu3Oy (SmBCO) films prepared by a low-temperature growth (LTG) technique. Despite the low-substrate temperature, the LTG-SmBCO films showed complete c-axis orientation and cube-on-cube texture. In addition, the LTG-SmBCO films showed a Jc of 0.28 MA/cm2 (77 K, B//c, B=5 T), because these included high-dislocation densities and nanosize low-Tc particles. In this study, we discuss the mechanism of c-axis orientation and crystal growth for high-Jc LTG-SmBCO films. We newly suggest a model for “Nucleated growth on c-axis oriented Seed layer (NCS)" to understand the c-axis orientation mechanism for LTG-SmBCO films. Based on the NCS model, when the LTG-SmBCO films nucleated on a seed layer have two-dimensional (2D) nuclei with a 1 unit SmBCO step cell height, the interfacial energy between the nucleus and the seed layer and the critical Gibbs free energy of the nucleus are lower than those of PLD-SmBCO films. Therefore, the LTG-SmBCO films show high crystal quality and a wide processing window for biaxial orientation. We suggest that the LTG technique is effective for not only increasing Jc in magnetic fields, but also improving the processing window and crystal quality.
