Deposition profile control of carbon films on patterned substrates using a hydrogen-assisted plasma CVD method
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1222-DD02-09
Fabrication, Transport and Raman Studies of Pulsed Laser Deposited Al/Ga Doped PBCO Thin Films Hom Kandel1,2, TarPin Chen2, HyeWon Seo2, Milko Iliev3, Paritosh Wadekar4, JingBiao Cui2 ShouZheng Wang2, Fumiya Watanabe5, Quark Chen4, Zhongrui Li5, Lixi Yuan2, Dever Norman1 1 Applied Science Department, University of Arkansas at Little Rock, Little Rock, AR, 72204, U.S.A. 2 Physics Department, University of Arkansas at Little rock, Little Rock, AR, 72204, U.S.A. 3 Texas Center for Superconductivity, University of Houston, Houston, TX, 77204, U.S.A. 4 Physics Department, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan, China. 5 Nanotechnology Center, University of Arkansas at Little Rock, Little Rock, AR, 72204, U.S.A.
ABSTRACT We have fabricated highly resistive materials PrBa2 (Cu1-xMx) 3O7 (M=Al, Ga, x = 0.20) by doping metals Ga and Al on PrBa2Cu3O7(PBCO). X-ray data indicated no significant second phases in substituting Cu by Al or Ga up to 20%.The electrical resistivity of these materials were three to four orders in magnitude higher than PBCO at 200K, which may give an effective potential barrier to YBCO in high Tc S-I-S Josephson junction. Epitaxial thin films of these materials were grown using KrF excimer laser on LAO (110) single crystal substrates. X-ray diffraction (XRD) and atomic force microscopy (AFM) were deployed to study the crystal orientation, epitaxy and roughness of the single crystal thin films. Micro Raman spectroscopy was carried out to investigate the dopant site in PBCO. INTRODUCTION Superconductor(S)-insulator(I)-Superconductor(S) tunneling Josephson junction is a key component of superconductor electronics with promising applications in defense, computing, remote sensors, single-electron transistors, quantum computing Qubits, terahertz frequency(THz) devices, electromagnetic(EM) sensors and biomedical imaging devices. These S-I-S junctions based on high temperature superconducting (HTSC) materials are operable at or above liquid nitrogen temperature (77K) eliminating an expensive and cumbersome liquid helium (4.2 K) cryogenics. This makes HTSC devices much more appealing for commercial use. However, until now, not many HTSC devices have been commercially available because of its low current density.YBa2Cu3O7 (YBCO) is the most widely studied HTSC due to its high Tc(92K) and mechanical/chemical stabilities. The intrinsic coherence length of YBCO is ~0.5nm along its caxis and ~4 nm along its ab-plane [1]. This short coherence length demands an extremely thin Ilayer in the junction which can also provide a sufficient potential barrier for the junction. PBCO, which behaves like semiconductor at room temperature but an insulator at low temperature [2], has been widely studied as an I-layer candidate in fabricating HTSC S-I-S Josephson junction because of its excellent lattice match, same process conditions, and identical thermal expansion coefficients with YBCO. The excellent lattice match reduces the strain of the YBCO film in the S-I-S junction and thus preserves its h
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