MOCVD法制备YBCO高温超导体所需前驱盐的制备研究

Study on the Precursors for MOCVD of High-T_c Superconductors YBCO

通过金属有机源化学气相沉积技术(MOCVD)已可制得Ic达280 A/cm,Ic×L为300330 A.m的高性能YBCO带材,表现出巨大的优势和诱人的应用前景。进一步提高前驱盐的挥发性和批次稳定性不但能降低YBCO带材的生产成本、也能提高其性能稳定性。本研究报道了MOCVD法制备YBCO所需β二酮中间体TMHD及其钇、钡、铜金属有机前驱盐的制备,通过红外光谱和核磁共振谱对其化学结构予以确认;同时以金属钡与TMHD在正戊烷或正己烷中制备了无水β-二酮钡盐(Ba[tmhd]2),随后用五乙烯六胺为辅助配体(L)制备了挥发性更好的无水复合配体钡盐(Ba[tmhd]2.L),并通过热重分析技术比较了各前驱盐的挥发性,结果表明:辅助配体五乙烯六胺对提高钡盐挥发性作用显著。

By metal organic chemical vapor deposition process （MOCVD） , the kilometer lengths of YB2Cu3Ox （YB- CO ） second-generation HTS wires with a minimum critical currents of 280A/cm corresponding to a record Ic × length value of 300330 A · mm has been obtained, and MOCVD technique showed great advantage and attractive prospect in YBCO manufacture of high throughput that enables large production capacity. However the conversion efficiency of MOCVD precursor need to be improved for reducing wire cost. In this work, the intermediate 2, 2, 6, 6-tetramethylheptane-3, 5- dionate （tmhd） and corresponding precursors for YBCO, including Y （tmhd） 3, Ba（tmhd） 2 and Cu （tmhd） 2, were synthesized and characterized by infrared spectrum （IR） and 1H nuclear magnetic resonance spectrum （^1H NMR）. Subsequently high volatile Ba（tmhd） 2 （penta） were obtained by using adduct molecule （ penta = pentaethlenehexamine）. Finally their volatility was investigated by thermogravimetry analysis （TGA）.