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Now showing 1 - 4 of 4
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    Pulsed laser deposition of thick BaHfO3-doped YBa 2Cu307-δ films on highly alloyed textured Ni-W tapes
    (Bristol : Institute of Physics Publishing, 2014) Sieger, M.; Hänisch, J.; Iida, K.; Gaitzsch, U.; Rodig, C.; Schultz, L.; Holzapfel, B.; Hühne, R.
    YBa2Cu3O7-δ (YBCO) films with a thickness of up to 3 μm containing nano-sized BaHfO3 (BHO) have been grown on Y2O3/Y-stabilized ZrO2/CeO 2 buffered Ni-9at% W tapes by pulsed laser deposition (PLD). Structural characterization by means of X-ray diffraction confirmed that the YBCO layer grew epitaxial. A superconducting transition temperature T c of about 89 K with a transition width of 1 K was determined, decreasing with increasing BHO content. Critical current density in self-field and at 0.3 T increased with increasing dopant level.
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    Investigation of the strain-sensitive superconducting transition of BaFe1.8Co0.2As2 thin films utilizing piezoelectric substrates
    (Milton Park : Taylor & Francis, 2014) Trommler, S.; Hänisch, J.; Iida, K.; Kurth, F.; Schultz, L.; Holzapfel, B.; Hühne, R.
    The preparation of biaxially textured BaFe1.8Co0.2As2 thin films has been optimized on MgO single crystals and transfered to piezoelectric (001) Pb(Mg1/3Nb2/3)0.72Ti0.28O3 substrates. By utilizing the inverse piezoelectric effect the lattice parameter of these substrates can be controlled applying an electric field, leading to a induction of biaxial strain into the superconducting layer. High electric fields were used to achieve a total strain of up to 0.05% at low temperatures. A sharpening of the resistive transition and a shift of about 0.6 K to higher temperatures was found at a compressive strain of 0.035%.
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    Universal scaling behavior of the upper critical field in strained FeSe0.7Te0.3 thin films
    (Bristol : Institute of Physics Publishing, 2018) Yuan, F.; Grinenko, V.; Iida, K.; Richter, S.; Pukenas, A.; Skrotzki, W.; Sakoda, M.; Naito, M.; Sala, A.; Putti, M.; Yamashita, A.; Takano, Y.; Shi, Z.; Nielsch, K.; Hühne, R.
    Revealing the universal behaviors of iron-based superconductors (FBS) is important to elucidate the microscopic theory of superconductivity. In this work, we investigate the effect of in-plane strain on the slope of the upper critical field H c2 at the superconducting transition temperature T c (i.e. -dH c2/dT) for FeSe0.7Te0.3 thin films. The in-plane strain tunes T c in a broad range, while the composition and disorder are almost unchanged. We show that -dH c2/dT scales linearly with T c, indicating that FeSe0.7Te0.3 follows the same universal behavior as observed for pnictide FBS. The observed behavior is consistent with a multiband superconductivity paired by interband interaction such as sign change s ± superconductivity.
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    Reversible shift in the superconducting transition for La1.85Sr0.15CuO4 and BaFe1.8Co0.2As2 using piezoelectric substrates
    (Milton Park : Taylor & Francis, 2010) Trommler, S.; Hühne, R.; Iida, K.; Pahlke, P.; Haindl, S.; Schultz, L.; Holzapfel, B.
    The use of piezoelectric substrates enables dynamic observation of the strain-dependent properties of functional materials. Based on studies with La1.85Sr0.15CuO4 (LSCO), we extended this approach to the iron arsenic superconductors represented by BaFe2− xCoxAs2 to investigate strain-driven changes in detail. We demonstrate that epitaxial thin films can be prepared on (001) Pb(Mg1/3Nb2/3)0.72Ti0.28O3 substrates using pulsed laser deposition. The structural and electric properties of grown films were characterized in detail. A reversible shift of the superconducting transition of 0.4 K for LSCO and 0.2 K for BaFe1.8Co0.2As2 was observed on applying biaxial strains of 0.022 and 0.017%, respectively.