Growth of Grain Oriented Ingot of High Critical Temperature Superconducting Oxides by Zone Refining

高温超导材料将允许以更低的功率需求开发各种各样的电子器件。该计划将产生1-2-3复合超导材料的大单晶；大单晶载流能力的增加将使高T_c材料得到实际应用。该计划第一阶段的目标是将微观微晶的尺寸扩大到可以从陶瓷材料中切割出来用作电路器件中的互连的尺寸。用来增加高T_c材料单晶尺寸的程序将利用在950℃时的初始微晶形成。通过在管式炉中形成温度梯度，可以实现较大微晶的固相外延生长。将在950摄氏度创建一个非常窄的区域(毫米长)，而管式炉的其余部分将保持在大约850摄氏度。这个狭窄的区域将沿着材料的长度缓慢移动，以允许更大的微晶的固相外延形成。通过研究陶瓷材料热处理过程中取向微晶的形成机理，可以达到获得较大微晶的目的。

High temperature superconductivity materials will permit development of a wide variety of electronic devices with decreased power requirements. This program will create large single crystallites of 1-2-3 compound superconductor material; increased current carrying capacity of large single crystals will allow a practical use of high Tc materials. The objective of Phase I of this program will be to enlarge the size of microscopic crystallites to a size such that they may be cut out of ceramic material and used as an interconnection in a circuit device. The procedure used to increase the size of single crystal form of high Tc material will take advantage of initial formation of crystallites at 950 degrees centigrade. Solid phase epitaxial growth of larger crystallites will be performed by developing a temperature gradient in a tube furnace. A very narrow zone (mm long) will be created at 950 degrees centigrade while the remainder of the tube furnace will be maintained at approximately 850 degrees centigrade. This narrow zone will be moved slowly along the length of the material to permit solid phase epitaxial formation of larger crystallites. The objective of obtaining larger crystallites will be attained by studying the mechanisms involved in creation of oriented crystallites in the heat treatment processing of ceramic materials.