Rare earth element complexes as a liquid precursor for (RE)Ba2Cu3Oy thin film by MOCVD

Low melting point rare earth (RE) elements (samarium, gadolinium, and ytterbium) complexes were newly synthesized as a precursor for fabricating superconducting (RE)Ba 2 Cu 3 O y thin films by MOCVD method; tris(2,2,6,6-tetramethyl-3,5-octanedionato)samarium (Sm(TMOD) 3 ), Gd(TMOD) 3 , and Yb(TMOD) 3 . The melting points of Sm(TMOD) 3 , 113 °C, Gd(TMOD) 3 , 104 °C, and Yb(TMOD) 3 , 98 °C, are 70 - 90 °C lower than those of the conventional tris(dipivaloylmethanato)RE (RE(DPM) 3 ). For fabricating (RE)Ba 2 Cu 3 O x thin films using RE(TMOD) 3 , a mixture of Ba(DPM) 2 and Ba(TMOD) 2 , 2, and bis(6-ethyl-2,2-dimethyl-3,5-octanedionato)copper (Cu(EDMOD) 2 ) were used. The precursors were heated higher than the melting point. By using precursors in the liquid state, stable deposition rates and film composition could be obtained. STO(100) single crystal was used as a substrate which was kept at a temperature of 800 C The XRD patterns indicate that the c-axis oriented SmBa 2 Cu 3 O y , GdBa 2 Cu 3 O y , and YbBa 2 Cu 3 O v thin films were obtained.