无氟MOD法制备YBCO超导薄膜工艺中物相的演变过程

Intermediate Phase Evolution in YBCO Superconducting Film Fabricated by Fluorine Free MOD Method

第二代高温超导带材在电力系统和磁体领域拥有良好的应用前景,无氟金属有机盐沉积技术(FF-MOD)以其设备成本低、晶体生长速率快、环境友好等特点,成为研究热点。本研究通过FF-MOD技术,在铝酸镧单晶和CeO_2/IBAD-MgO/Y_2O_3/Al_2O_3/HastelloyC276人工基板上制备得到钇钡铜氧(YBCO)薄膜,并对不同制备温度下的样品进行淬火,随后对淬火样品进行了X射线衍射、扫描电子显微镜和衰减全反射红外光谱的表征,系统地研究了高温成相过程中BaCO_3和YBCO的相演变过程。实验结果表明,在YBCO成相过程中,BaCO_3不会与Y、Cu元素的氧化物反应直接生成YBCO晶体,并生成的YBCO相晶体先呈随机取向,然后在热处理的过程中(800℃左右)逐渐转化为具有双轴织构的YBCO晶体。

The second generation of high temperature superconducting tape is considered to be a promising material for future power and magnet applications. Among the fabrication processes, Fluorine Free-Metal Organic Deposition（FF-MOD） method has received much attention in recent years because of its low equipment requirements, high crystal growth rate, and environmental friendliness. In present study, yttrium barium copper oxide（YBCO） films were prepared on the LAO single crystals and CeO2/IBAD-MgO/Y2O3/Al2O3/Hastelloy C276 technical substrates by the FF-MOD technique. The samples were quenched at different temperatures and then characterized by X-ray diffraction, scanning electron microscope and ATR-FT-IR to inveitigate the phase evolution process of YBCO and BaCO3. The results demonstrate that YBCO crystal does not formed directly by reaction between BaCO3 and Y/Cu oxides. And the formed YBCO crystals are randomly oriented at first, and then gradually convert into the biaxially textured structure during the heat treatment process at about 800℃.