A study of the optimization of sputtering and sintering parameters for the growth of Tl2Ba2Ca2Cu3O10+χ superconducting films

Abstract Thin superconducting films of Tl-2223 were grown on YSZ, MgO, LaAlO 3 and SrTiO 3 single crystal (001) faces using a single target RF magnetron sputtering source and different geometrical configurations. The sputtered films were post annealed in various crucibles (Al 2 O 3 , Pt) and in gas atmospheres composed of Ar/O 2 mixtures. XRD, EDAX, SEM, AES and Raman spectroscopy were used to characterize the quality of the resulting films. These examinations have yielded a simplified phase diagram correlating the sintering temperature ( T s ), and a parameter β (β= f (O 2 )/[ f (O 2 ) + f (Ar)]), that characterizes the oxidizing-reducing properties of the gaseous atmosphere used during sintering, with the resulting film phase-content, structure and morphology. A specific “time-window” for optimal film sintering with respect to the highest T c has been found for the experimental arrangement used. The highest critical temperature observed in the Tl-2223 films was ~ 114 K ( R =0) and the critical current density at 77 K reached ~5×10 4 A/cm 2 .