The effects of the post-annealing time on the growth mechanism of Bi2Sr2Ca1Cu2O8+ thin films produced on MgO (100) single crystal substrates by pulsed laser deposition (PLD)

摘要

Bi2Sr2Ca1Cu2O8+δï thin films were deposited on MgO (100) substrates by pulsed laser deposition (PLD). The effects of post-annealing time on the phase formation, the structural and superconducting properties of the films have been investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature dependent resistivity (R-T), atomic force microscopy (AFM), and DC magnetization measurements. The films deposited at 600 °C were post-annealed in an atmosphere of a gas mixture of Ar (93%) and O2 (7%), at 860 °C for 10, 30, and 60 min. All films have demonstrated a mainly single phase of 2212 with a high crystallinity (FWHM0.159°) and c-axis oriented. The critical temperature, TC, of the films annealed for 10, 30, and 60 min were obtained as 77, 78, and 78 K, respectively. The highest critical current density, JC, was calculated as 3.34×107 A/cm2 for the film annealed at 860 °C for 30 min at 10 K.