在溶胶-凝胶法中甲酰胺的添加量对Tl-2212超导薄膜的影响

Effects of Formamide Addition Amount on Tl-2212 Superconducting Films by a Sol-gel Method

以乙酸盐为起始原料,甲醇为溶剂,甲酰胺为添加剂,在铝酸镧(LAO)(00l)衬底上生长Tl2Ba2CaCu2O8(Tl-2212)超导薄膜。结果表明,在溶胶中加入甲酰胺,对先驱膜的形貌,以及超导薄膜的形貌、结构、性能有较大影响;当甲酰胺添加量为甲酰胺:乙酸钡(摩尔比)=(15~25):1时,可以制备出具有致密的晶体结构、高度c轴取向的外延Tl-2212超导薄膜,其薄膜具有较好的电学性能,临界温度Tc可达105.8K,临界电流密度Jc可达0.75MA/cm2(77K,0T)。

Tl_2Ba_2CaCu_2O_8(Tl-2212) superconducting films were grown on LaAlO_3(001) substrates by a sol-gel method in which the required sol was prepared using methanol as solvent, acetates as starting materials, and formamide as chemical additives. Results show that the addition amount of formamide has a great influence on the morphology of precursor, phase structure and property of Tl-2212 films. With formamide adding amount of formamide: barium acetate(mole ratio) =(15~25):1, Tl-2212 superconducting films can be prepared. The films possess excellent c-axis orientation, dense crystal structure and excellent electrical property. The critical temperature Tc of the best sample is around 105.8 K, and the critical current density Jc around 0.75 MA/cm2(77 K, 0 T).