YBa_2Cu_3O_(7-y)超导体激光改性的研究

INVESTIGATION ON LASER MODIFICATION FOR YBa_2 Cu_3 O_(7-y) SUPERCONDUCTOR

研究了利用激光对YBa_2Cu_3O_(7-x)块材进行改性处理。经激光熔融的YBa_2Cu_3O_(7-x)样品分解成BaCuO_2和Y_2Cu_2O_5。熔融样品在O_2中退火后,经过氧的连接又生成YBa_2Cu_3O_(7-x)超导体,说明O_4在123相中不仅起了耦合Cu_1与Cu_2层对超导电性起作用,而且起了支撑晶体结构的作用。经激光改性后的样品,晶粒细化均匀,有序化程度提高,改善了弱连接,其临界电流密度比处理前提高了一倍。而且未烧结的混合样品经激光改性后,变成超导体,T_c=93K,J_c～100A/cm^2有可能为制备超导带材和线材的一个方法。

The modified YBa2Cu3O7_y bulk by laser have been studied.when laser irradiates superconducting samples, the YBa2Cu3O7-y are resolved into Y2Cu2O5 and BaCuO2.After the irradiated samples were annealed in O2 the YBa2Cu3O7 Y superconductor are formed once again.This indicates that O4 in 123 phase are not only play important role in superconductivity for coupling Cul andCu2 layers but also do in holding crystal structure.In modified aud annealed samples, grains become fine, homogeneous and ordering.The critical current density have obviously increase for the modified samples.It is interested that pressed disks without sinter do come superconductor after laser irradiating and annealing in O2 with Tc = 92K, and Jc-100A/cm2.