Growth process and microstructure of Y123 film fabricated by advanced TFA-MOD process

Abstract

The advanced metal organic deposition (MOD) process using F-free salt of Cu and trifluroacetates (TFA) salts (Superconductivity Research Laboratory (SRL)-Method) was applied to form well oriented Y123 film on LaAlO3 substrate. In order to clarify the growth mechanism of the Y123 film by the advanced TFA-MOD process, two methods were introduced. One was the quenching method to get samples under several different conditions during the process, and the microstructures were observed by transmission electron microscopy (TEM). The other was in situ observation method to know surface changes of the film by the generation of liquid and/or gas. From the θ–2θ X-ray diffraction (XRD) analysis of YBa2Cu3O7−δ (YBCO) films fabricated by suitable conditions, (00n) diffraction peaks were obtained indicating they had strongly c-axis oriented structure. The thin YBCO films had critical current density (JC) of 3.8–4.9MA/cm2 (77K,0T) measured by the four-probe-method. A growth model with some process-controlling parameters was proposed based on the above observed results.