Shanghai Creative Superconductor Technologies Co.

Shanghai, China

Shanghai Creative Superconductor Technologies Co.

Shanghai, China
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Li M.,Shanghai University | Fang Q.,Shanghai University | Hu X.,Shanghai University | Liu Z.,Shanghai University | And 9 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2017

YEuxBa2Cu3.6O7−δ(x = 0, 0.1, 0.3, 0.5) thin films were prepared on buffered substrates by trifluoroacetate metal organic deposition (TFA-MOD). The europium-doped film showed better out- and in-plane texture than the pure YBa2Cu3.6O7−δ thin film and special topography. In the meantime, the superconducting transition temperature Tc was improved with the increase of europium content and spanned a small range when x= 0.5 doping levels. Besides, the Jc value was obviously enhanced with europium addition, and YEu0.3Ba2Cu3.6O7−δ showed the best superconducting properties under self-field. Furthermore, the Jc value was obviously improved under magnetic field, and the enhanced flux-pinning properties was also observed in europium-substituted samples which may be attributed to the good grain connections and the effective flux pinning centers introduced by europium addition. The thickness of prepared film samples were approximately 400 nm. The structure of samples were characterized by x-ray diffraction (XRD), Raman spectrum was used to investigate the crystallization and growth orientation, and the surface morphology of films were got by field-emission scanning electronic microscopy (FE-SEM). Moreover, energydispersive spectroscopy (EDS) was utilized to determine element composition. Spatial distribution of Jc of the film was obtained by mapping analysis of inductive measurement at 77 K. And the superconducting properties under magnetic fields were measured by magnetic property measurement system with a SQUID magnetometer. © 2016, Springer Science+Business Media New York.


Jian H.,Shanghai UniversityShanghai | Jian H.,Shanghai Creative Superconductor Technologies Co. | Zhong H.,Shanghai Creative Superconductor Technologies Co. | Liu X.,Shanghai Creative Superconductor Technologies Co. | And 13 more authors.
Physica C: Superconductivity and its Applications | Year: 2017

Oxygenation is one of the most essential processes for practical applications of REBa2Cu3O7−δ (RE123, RE = Y, Gd etc. rare earths) superconductors. Second generation high-Tc superconducting coated conductors are based on biaxial textured RE123 thin films, on which, a cover layer of silver for protecting is normally applied. It results in a little more complicated oxygenation process compared to naked film without silver protective layer. In the present work, a series of absorbing oxygen post-annealing processes were carried out for YBa2Cu3O7−δ coated conductors. The oxygen diffusion procedure and the kinetics in the annealing process were investigated. Analysis and calculations show that the activation energy was 1.01 eV, consistent with previous reports. Moreover, experiments show that the “over-doping” phenomena frequently occurs in coated conductors, and thus dropping the Tc to as low as 86–88 K. To improve the temperature margin for practical applications (temperature difference between the superconducting transition temperature Tc and application temperature), we investigated the potential of increase in Tc by preventing from the “over-doped” happening, while keeping oxygen in order. Finally, by employing the new annealing process, we can produce long (several hundred meters) coated conductor with high Tc,onset (92 K), narrow transition width and stable performance. © 2017


Shi X.L.,Shanghai University | Fan F.,Shanghai University | Fan F.,Shanghai Creative Superconductor Technologies Co. | Guo Y.Q.,Shanghai University | And 9 more authors.
2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2015 - Proceedings | Year: 2015

Biaxially texture magnesium oxide (MgO) films have been grown using ion beam assisted deposition (IBAD). IBAD-MgO films can easily to grow in the preferred direction and to form biaxial texture fast by the effect of ion beam assisted current, where the ability of preferred growth is directly controlled by the ion beam assisted current. An in situ reflection high energy electron diffraction (RHEED) has often been used to monitor the texture development of MgO film during the IBAD process. Here, we developed novel numerical analysis methods for RHEED patterns based on gray level. We constructed corresponding gray scale images and binary images from RHEED patterns. The area and brightness of selected diffraction spots, such as (004) diffraction spots, were measured based on the gray scale images. Further, rich information on the whole RHEED binary images, such as high-brightness pixels proportion of gray value higher than 50% gray level, can be obtained. Results from these qualitative analyses of RHEED patterns were coincided to the texture evolution obtained by phi scan rocking curves. This indicates these kinds of analysis methods based on gray level are effective for RHEED patterns. © 2015 IEEE.


Dou W.,Shanghai University | Liu Z.,Shanghai University | Liu Z.,Shanghai Creative Superconductor Technologies Co. | Peng C.,Shanghai Creative Superconductor Technologies Co. | And 8 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2016

This work presents a study of the evolution of the phases in the intermediate heat treatment process (IHP) which was after the pyrolysis process and before the crystallization of YBCO superconducting thin films. It was shown that the evolution of the solid solution could always take place whether with or without water vapor and oxygen. When water vapor is present in the atmosphere, the evolution temperature of the intermediate phase was lower than the one without vapor. The intermediate phase of Y2Cu2O5 with the vapor was observed at 680 °C. By calculating the changes of Gibbs free energy of reactions possibly involved in the IHP, the priority reaction with water vapor was CuF2>YF3>BaF2 when CuF2, YF3, and BaF2 coexisted while CuF2 and YF3 prefer to react with BaO to form BaF2 while they coexisted. The appearance of intermediate phase features could be illustrated through the calculation. © 2016 Springer Science+Business Media New York


Li M.Y.,Shanghai University | Liu Z.Y.,Shanghai University | Liu Z.Y.,Shanghai Creative Superconductor Technologies Co. | Fang Q.,Shanghai University | And 8 more authors.
Physica C: Superconductivity and its Applications | Year: 2016

The critical current density (Jc) performance of YBCO coated conductors (CCs) under magnetic field has become a considerable limitation for its commercial application in recent years. It is well known that the proper amount of element doping into the CCs is a convenient method to increase flux pinning and then to enhance the Jc. In the present work, we firstly introduce the co-doping of Eu and Hf and study the effect on the performance of YBa2Cu3.6O7-δ thin films. Three types of high temperature superconducting thin films, i.e., YBa2Cu3.6O7-δ, (Y,Eu)Ba2Cu3.6O7-δ and Hf doped (Y,Eu)Ba2Cu3.6O7-δ were prepared on the oxide buffered metallic substrates by using trifluoroacetate metal organic deposition (TFA-MOD). The component and structure of the as-prepared samples were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and atomic force microscopy (AFM). Superconducting properties were measured with a SQUID magnetometer. It was revealed that the (Y,Eu)Ba2Cu3.6O7-δ thin films exhibit better out-plane and in-plane texture compared with the pure YBa2Cu3.6O7-δ thin film. The Jc of (Y,Eu)Ba2Cu3.6O7-δ thin film was improved compared with pure YBCO thin film. In case of Hf doping, however, the biaxial texture became worse while the in-field Jc performance was enhanced, implying the increase of flux pinning with proper Hf addition. © 2016 Elsevier B.V.


Guo Y.Q.,Shanghai University | Guo Y.Q.,Shanghai Creative Superconductor Technologies Co. | Chi C.X.,Shanghai University | Shi X.L.,Shanghai University | And 7 more authors.
2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2015 - Proceedings | Year: 2015

Coated conductor based on epitaxial growth of thin films usually demands highly clean, smooth and flat Ni-based metal tape as the substrate. The surface quality of Ni-based alloy is typically assessed by atomic force microscopy (AFM). However, many complex local surface features can not be reflected adequately by conventional statistic parameters such as overall root mean square (RMS) roughness. Here, we developed a numerical analysis method for AFM images based on height histogram or gray histogram to gain more insight into surface features by evaluating the degree of surface flatness. Compared to conventional statistical RMS roughness, binary image with the flat area fraction gives more information on surface flatness. The degree and distribution of surface flatness can be reflected vividly by binary image with the percentage of flat area. This numerical analysis for surface flatness based on height histogram or gray histogram was demonstrated using Ni-based alloy as a paradigmatic example, which can also be applied to AFM images of other solid materials. © 2015 IEEE.


Cui C.-W.,Shanghai University | Cui C.-W.,Shanghai Creative Superconductor Technologies Co. | Yang W.-T.,Shanghai University | Liu Z.-Y.,Shanghai University | And 8 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2016

An approach based on the insertion of a CuO layer in YBa2Cu3O7-d (YBCO)-coated conductor was proposed and demonstrates high current-carrying ability. The multilayer architecture was deposited on oxid-buffered Hastelloy tapes using a metal organic deposition (MOD) process (low-fluorine solution route). It was revealed that the introduction of a CuO layer was effective to avoid the presence of a-axis grain and pores of the YBCO films, which were frequently observed in multilayer films. Presently, the thickness of the multilayer films was almost 1.5 µm. Based on the improvements of the surface quality and c-oriented texture which were proved by X-ray (??-2??, f, and ?)-scan, AFM images, and SEM (surface and cross-section) images, the critical current density (Jc) of YBCO films with middle CuO and bottom CuO are 2.0 MA/cm 2 and 2.5 MA/cm 2 (at 77 K, self-field), respectively. © 2016 Springer Science+Business Media New York


Rui R.-S.,Shanghai University | Rui R.-S.,Shanghai Creative Superconductor Technologies Co. | Liu Z.-Y.,Shanghai University | Liu Z.-Y.,Shanghai Creative Superconductor Technologies Co. | And 7 more authors.
Wuji Cailiao Xuebao/Journal of Inorganic Materials | Year: 2014

Trifluoroacetate metal organic deposition (TFA-MOD) is one of the most promising technology routes for fabrication of YBa2Cu3O7-δ (YBCO) coated conductors. In this paper, high-boiling point organic solvent diethanolamine (DEA) was added to modulate and to improve the properties of precursor solution by suppression the defect in the final films. And the thickness of single coated film was increased by increased concentration of the metal ions in the precursor solution. It is revealed that an exponential relationship was found between the thickness of precursor film after low-temperature decomposition and the ion concentration, as well as the viscosity of precursor solution vs the ion concentration. Optimizing the ion concentration and dip-coating parameters, smooth and crack-free YBCO films after crystallization are achieved with the thickness more than 1.3 μm. The films show homogeneous microstructures while dispersive heterogeneous particles appear in the surface of the thick films. Critical current density (Jc) measurement shows a decrease of Jc due to the increase of the thickness of YBCO films prepared by high concentration precursor solution, while critical currents (Ic) are distinctly improved. For instance, the Ic value of YBCO film prepared by 2.5 mol/L precursor solution is 4.7 times of that by 1.0 mol/L precursor solution. ©, 2014, Science Press. All right reserved.


Cui C.-W.,Shanghai University | Cui C.-W.,Shanghai Creative Superconductor Technologies Co. | Liu Z.-Y.,Shanghai University | Liu Z.-Y.,Shanghai Creative Superconductor Technologies Co. | And 7 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2016

DyBa2Cu3O7−δ/YBa2Cu3O7−δ multilayer thick films were prepared on oxide-buffered Hastelloy substrates by low fluorine metal organic deposition (MOD) process with a thickness ranging from 0.7 μm to 2.8 μm. In the thickness of 1.4 μm sample, transition temperature (Tc) and critical current density (Jc) are 91.2 K and 2.5 MA/cm 2 (at 77 K, self field) respectively. With increasing thickness, Tc drops as well as Jc. Unfortunately, the critical current (Ic) does not reach an ideal value when the thickness is 2.8 μm just only 365A/cm width as thickness is 2.1 μm. Rough surface structure, compressive, and tensile stress in the interlamination and Ba-Cu-O mixed phase were found in layer thickness of 2.1 μm and 2.8 μm are assumed to be the main reason for the limitation of the current transport. © 2016 Springer Science+Business Media New York


PubMed | Shanghai Creative Superconductor Technologies Co. and Shanghai University
Type: Journal Article | Journal: SpringerPlus | Year: 2016

BaHfO

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