Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
Department of Materials Physics, Institute of Experimental Physics, Slovak Academy of Science, Watsonova 47, Košice 04001, Slovakia.
IUCrJ. 2023 Mar 1;10(Pt 2):177-188. doi: 10.1107/S2052252523000076.
Self-repair, as a natural phenomenon, has been vastly observed and investigated in a variety of fields. With such an ability, living species self-heal their wounds to restore physiological functions while non-biological materials return to their original states, for example, thin surface layer growth occurs in the regeneration of incomplete KHPO crystals. Here, two seeding strategies are developed for creating incomplete crystallographic shapes (i.e. right-angled concave corners) of YBaCuO (YBCO) superconducting crystals with self-repairing capability in top-seeded melt growth. One involves in situ self-assembly seeding, by which the ability to self-repair promotes YBCO growth; the other is vertically connected seeding, by which self-repair triggers YBCO nucleation. Consequently, rapid surface crystallization originated at concave corners and swiftly generated initial growth morphology approaching equilibrium. Furthermore, these rapid-growth regions including the concave crystal or seed innately functioned as sizable effective seeding regions, enabling the enlargement of the c-oriented growth sector and the enhancement of properties for YBCO crystals. This work demonstrates experimentally that biaxial-in-plane-aligned crystals and precisely perpendicular-arranged seeds are important self-repairing activators for the rapid growth of YBCO crystals. This nature-inspired self-repairing work offers insights into the design of seeding architecture with non-equilibrium morphology for inducing sizable high-performance crystals in the YBCO family and other functional materials.
自修复作为一种自然现象，在许多领域都得到了广泛的观察和研究。具有这种能力的生物可以自行修复伤口以恢复生理功能，而非生物材料则可以恢复到原来的状态，例如在 KHPO 晶体不完全再生过程中，薄的表面层生长。在这里，开发了两种成核策略，用于在顶部籽晶熔融生长中创建具有自修复能力的 YBaCuO（YBCO）超导晶体的不完全晶体形状（即直角凹角）。一种是原位自组装成核，其中自修复能力促进 YBCO 生长；另一种是垂直连接成核，其中自修复触发 YBCO 成核。因此，快速的表面结晶起源于凹角，并迅速产生接近平衡的初始生长形态。此外，这些快速生长区域包括凹角晶体或种子，本能地充当大规模有效成核区域，从而扩大 c 取向生长区域并增强 YBCO 晶体的性能。这项工作通过实验证明，双轴面内取向晶体和精确垂直排列的种子是 YBCO 晶体快速生长的重要自修复激活剂。这项受自然启发的自修复工作为设计具有非平衡形态的成核结构提供了思路，可用于诱导 YBCO 族和其他功能材料中具有大规模高性能的晶体。
