We fabricated YBCO film using a TFA-MOD method. In order to enhance the reaction kinetics and to control the formation of the second phases, and powders were used as precursors (the so called "211 process"). The films were calcined at and then fired at in a 12.1% humidified atmosphere. We found that the microstructure varied significantly with the firing temperature. The textures of all of the films were similar and mainly biaxial. For the film fired at , the critical current was obtained to be 39 A/cm-width (corresponding critical current density is 2.0 MA/).

Electromagnetic properties of doped and undoped YBaCuO superconductors were evaluated to investigate the effect of pinning center on the magnetization and magnetic shielding. The variation with doping was maximum for 3% doping and decrease with further doping. The magnetic shielding was evaluated by measuring the induced voltage in secondary coil and the voltage initially set to 0.5V, decreased to 0.17V and 0.28V respectively for the undoped and 3% doped sample. The much less change in the induced voltage for the 3% doped sample is attributed to the increased flux shielding by shielding vortex current. The was converted to fine particles which were trapped in YBaCuO superconductor during the reaction sintering. The trapped fine particles, may be acted as a flux pinning center.

Distribution of (211) Particles within (123) grains of melt infiltration processed YBCO oxides was investigated. Processing parameters were a temperature, atmosphere (air and ) and initial 211 size. The 211 particles were distributed randomly within the 123 grains when the initial 211 size was large, while they made x-like pattern and/or butterfly-like patterns when the 211 size was small. The 211 patterns were more clearly observed in the samples prepared at higher temperatures and under atmosphere. The 211 distribution was explained in terms of the interfacial energy relationship among the solid, particle and melt.

We have evaluated the role of Ag additions on the strength, fracture toughness, elastic modulus and resistance to thermal shock of (YBCO) superconductor. Addition of 10 vol.% Ag improved strength and fracture toughness, whereas, decreased elastic modulus of YBCO. In addition, YBCO-Ag composites improved resistance to thermal shock probably due to enhanced strength, fracture toughness and thermal conductivity as a result of Ag addition. It is to be noted that YBCO-Ag made by mixing with solution showed slightly higher strength, fracture toughness and resistance to thermal shock, compared to that made by mixing with metallic Ag powder. These improvements are believed to be due to the microstructure of more finely and uniformly distributed Ag particles.

은(Ag)의 첨가가 YBa2Cu3O7-δ (YBCO) 고온초전도체의 미세조직, 기계적 및 전기적 성질에 미치는 효과를 연구하였다. 소량의 Af(5, 10, 15 vol.%)는 각각 금속분말상태와 질산염인 AgNO3초전도체의 강도와 인성값이 Ag의 함량이 증가할수록 높게 나타났으며, 이는 Ag입자에 의해 야기되는 강화기루에 의한 것으로 생각된다. 또한 Ag를 질산염의 분말상태로 첨가하여 만든 YBCO-Ag 복합재료가 금속분말상태로 첨가하여 만들었을 때보다 강도 및 인성값이 더 우수한 것으로 나타났다. AgNO3를 첨가한 복합체가 상대적으로 더 우수한 기계적 성질을 가지는 것은 Ag 입자가 더 미세하고 균일하게 분포되었기 때문으로 판단된다. Ag 첨가로 인해 YBCO 복합초전도체의 전류밀도값은 미세하게 증가하는 것으로 관찰되었다.