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We observe and measure the inductance of long intrinsic Josephson junction arrays composed of misaligned Tl2Ba2CaCu2O8 thin films grown on LaAlO3 substrates. The array consists of about 9.1×103 intrinsic Josephson junctions, where 90° phase shift between ac voltage across the array and ac current flowing through has been measured. Furthermore, the voltage is proportional to the frequency of the current. The measured inductance values of the intrinsic Josephson junction arrays are basically consistent with the theoretically calculated results, confirming that the inductance is mainly due to the Josephson effect. The dependence of the array inductance on its critical current is also discussed.

Tl2Ba2CaCu2Ox (Tl-2212) thin films were prepared by the two-step technique. A precursor film was first prepared by the pulsed laser deposition method, and then experienced the incorporation of thalliation in a one-step or two-step annealing process. The experimental results show that the two-step annealing process produces dense and smooth films, and that the one-step annealing process produces a high critical temperature film of 101K, but the transition width is wide. Precursor films with homogeneous Ba2Ca1.3Cu2.1Ox composition are essential for producing high-quality Tl-2212 films.

The reoccurrence of pits has been found on the surfaces of c-axis YBa2Cu3O7-? (YBCO) films grown epitaxially on 10? vicinal SrTiO3 substrates by pulsed laser deposition. They are always associated with films with a step-terrace structure, while polycrystalline films have no pits. Pit formation is attributed to the large interfacial stress induced by vicinal substrate and oxygen deficiency of the YBCO film during the tetragonal-to-orthorhombic (T-O) phase transition, which cannot be released by forming twins, and leads to rupturing of the film surface. By reducing the oxidation partial pressure for the T-O phase transition to 80?Pa, no pits were formed, and the YBCO film is superconducting at 60?K. PACS: ?62.?20.?Hk, 74.?76.?Bz, 81.?15.

We investigate the self-emissions from serial high-temperature superconductor bicrystal Josephson junction arrays embedded in a quasi-optical resonator. A bicrystal substrate is used as a dielectric resonator antenna, which increases the coupling strength between the junction array and the electromagnetic (EM) wave. Both three-dimension (3D) electromagnetic simulations and experiments are performed. Strong off-chip radiations are measured from the junction array at 78 GHz and 78 K. The proposed method and the experimental results are important for millimeter wave applications in junction arrays.

The double-side Tl2 Ba2 CaCu2O8 (Tl-2212) superconducting thin films were fabricated on CeO2 buffered sapphire substrates. The reactive magnetron sputtering technique was used to grow CeO2 buffer thin films on sapphire substrates. Making use of the metal cerium as a sputtering source, the depositing rate is much higher compared with the CeO2 target. The Tl-2212 thin films on CeO2 buffered sapphire substrates were fabricated by a dc magnetron sputtering and post-annealing process. The x-ray diffraction indicates that the thin film is pure Tl-2212 phase with the c-axis perpendicular to the substrate surfaces, and epitaxially grown on the CeO2 buffered sapphire. The critical transition temperature Tc is around 106K, the critical current density Jc is around 3.5MA/cm2 at 77K, and the microwave surface resistance Rs at 77K and 10 GHz of the film is as low as 390 μΩ.