Yttrium Barium Copper Oxide Single Crystals for Flux-Trapping Applications

这个小企业创新研究第一阶段项目涉及先进超导陶瓷材料的合成和加工领域的研究。这项工作的主要目的是优化高温超导陶瓷（HTSC）粉末的化学计量学、相组成、形态和其他特性，用于生产高质量的单晶，具有高临界电流密度，这是磁通捕获应用所必需的。一个重要的附加目标是促进对某些晶体生长过程参数的更好理解的发展，这些参数被认为是控制生长速率和单晶性质的最重要的参数。这项工作将集中在已知具有有用超导特性的YBa2Cu3O7（123）材料上，这种材料已经在美国和日本成功地制成了单晶。粉末将使用经过验证的燃烧喷雾热解（CSP）方法生产，该方法能够提供高纯度，超细，具有一致重复性的化学计量粉末。还将生产用于生长123单晶的Y2BaCuO5（211）粉末，以及123/211复合成分。通过检查将金属引入前驱体粉末的适当方法，将探讨少量添加铂对晶体生长过程的公认作用。将确定生产优选前驱体粉末所需的CSP工艺的必要修改。所选的粉末将用于随后将在普林斯顿大学进行的单晶生长实验（改良的Czochralski生长法）。单晶生长技术将从普林斯顿大学转移到SSC公司，继续开发并最终商业化。

This Small Business Innovation Research Phase I project involves research in the area of synthesis and processing of advanced superconducting ceramic materials. The principal objective of the proposed work is to optimize the stoichiometry, phase composition, morphology, and other characteristics of high-temperature superconducting ceramic (HTSC) powders used to produce high-quality single crystals having high critical current densities necessary for flux-trapping applications. An important additional objective is to contribute to the development of an improved understanding of certain crystal growth process parameters thought to be of prime importance in controlling growth rates and single crystal properties. The work will be concentrated on YBa2Cu3O7 (123) materials known to have useful superconducting properties and which have already been successfully fabricated as single crystals, both in the United States and in Japan. The powders will be produced using a proven combustion spray pyrolysis (CSP) method capable of providing high-purity, ultra-fine, stoichiometric powders with consistent reproducibility. Y2BaCuO5 (211) powders used in the growth of 123 single crystals, as well as 123/211 composite compositions, will also be produced. The recognized role of small additions of platinum to the crystal growth process will be explored by examining appropriate means for introducing the metal into the precursor powders. Required modifications to the CSP process required to produce preferable precursor powders will be established. Selected powders will be used in subsequent single crystal growth experiments (modified Czochralski growth method) to be conducted at Princeton University. Single crystal growth technology will be transferred from Princeton University to SSC, Inc. for continuing development and eventual commercialization as progress warrants.