Characterization of sputtered films of Tl2Ba2CaCu2O8 using Raman scattering and x-ray diffraction

Characterization of films prepared by laser ablation of precursor targets andex situthalliation

“…The Raman spectra (figure 3), like the x-ray patterns, showed only a pure and highly c-axis-oriented Tl-2212 phase. However, the presence of the Ramanactive feature centred at ∼ 555 cm −1 , which was identified previously as originating from a Tl-2212 amorphous matrix residuum and a disorder-activated IR active vibration [3], indicates again a substantial disorder in the lattice of the annealed film. Also, EDAX data and AES depth profiles suggested that the films contained numerous point defects.…”

“…Thallium-based thin superconducting films are considered to be very promising materials for the fabrication of various passive microelectronic devices (bandfilters, resonators, etc) due to their high critical temperature, T c , high critical current density, j c , and particularly low surface impedance at 77 K [1]. These features have been the motivation for the exploration of various methods of film fabrication such as RF sputtering [2,3], e-beam evaporation [4], thermal evaporation [5] and laser ablation [6,7]. The last method seems to be the most attractive, in that it enables one to deposit a ∼ 0.3-0.5 µm thick film in a short time (∼ 10-15 min) which is at least a factor of 10 shorter than the time needed for other methods (for example RF sputtering).…”