Some Properties of High-Tc Oxide Superconducting Thin Films
High Tc superconducting LnBaCuO (Ln: Ho,Er,Y), BiSrCaCuO and TlBaCaCuO films have been produced by rf magnetron sputtering using single composite targets.
X-ray, RHEED and SEM analyses show that LnBaCuO films made on MgO (001) are epitaxially grown single crystals with extremely smooth surface6. The critical current densities in the LnBaCuO films at 77.3 K are excess of 3x106 A/cm2 . Highly textured c-axis-oriented poly-crystalline BiSrCaCuO films around the cation ratio 2:2:2:3 having Tc (zero-resistance temperature) of 105 K show critical current densities of 1.9x106 A/cm2 at 77.3 K and 2.1x107 A/cm2 at 40 K. In TIBaCaCuO films having a maximum Tc of 109K (zero-resistance temperature), a critical current density of 3.2x106 A/cm2 at 77.3 K was obtained.
KeywordsCritical Current Density Magnetic Field Dependence Parallel Magnetic Field RHEED Pattern Secondary Electron Detector
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