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Author Pahlke, P.; Sieger, M.; Ottolinger, R.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Haenisch, J.; Holzapfel, B.; Schultz, L.; Nielsch, K.; Huehne, R. pdf  url
doi  openurl
  Title Influence of artificial pinning centers on structural and superconducting properties of thick YBCO films on ABAD-YSZ templates Type A1 Journal article
  Year (down) 2018 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech  
  Volume 31 Issue 4 Pages 044007  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Recent efforts in the development of YBa2Cu3O7-x (YBCO) coated conductors are devoted to the increase of the critical current I-c in magnetic fields. This is typically realized by growing thicker YBCO layers as well as by the incorporation of artificial pinning centers. We studied the growth of doped YBCO layers with a thickness of up to 7 mu m using pulsed laser deposition with a growth rate of about 1.2 nm s(-1). Industrially fabricated ion-beam textured YSZ templates based on metal tapes were used as substrates for this study. The incorporation of BaHfO3 (BHO) or Ba2Y(Nb0.5Ta0.5)O-6 (BYNTO) secondary phase additions leads to a denser microstructure compared to undoped films. A purely c-axis-oriented YBCO growth is preserved up to a thickness of about 4 mu m, whereas misoriented texture components were observed in thicker films. The critical temperature is slightly reduced compared to undoped films and independent of film thickness. The critical current density J(c) of the BHO- and BYNTO-doped YBCO layers is lower at 77 K and self-field compared to pure YBCO layers; however, I-c increases up to a thickness of 5 mu m. A comparison between films with a thickness of 1.3 mu m revealed that the anisotropy of the critical current density J(c)(theta) strongly depends on the incorporated pinning centers. Whereas BHO nanorods lead to a strong B vertical bar vertical bar c-axis peak, the overall anisotropy is significantly reduced by the incorporation of BYNTO forming a mixture of short c-axis-oriented nanorods and small (a-b)-oriented platelets. As a result, the J(c) values of the doped films outperform the undoped samples at higher fields and lower temperatures for most magnetic field directions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000442196400001 Publication Date 2018-02-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-2048 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.878 Times cited 9 Open Access OpenAccess  
  Notes ; The authors acknowledge financial support from EURO-TAPES, a collaborative project funded by the European Union's Seventh Framework Programme (FP7/ 2007-2013) under Grant Agreement no. 280432. We thank A Usoskin (Bruker HTS GmbH, Germany) for the provision of buffered templates, and M Bianchetti, A Kursumovic and J L Mac-Manus-Driscoll (University of Cambridge, UK) for the supply of BYNTO targets. The authors also gratefully acknowledge the technical assistance of J Scheiter, M Kuhnel, U Besold (IFW) and R Nast (KIT). ; Approved Most recent IF: 2.878  
  Call Number UA @ lucian @ c:irua:153775 Serial 5108  
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Author Sieger, M.; Pahlke, P.; Lao, M.; Meledin, A.; Eisterer, M.; Van Tendeloo, G.; Schultz, L.; Nielsch, K.; Huehne, R. pdf  doi
openurl 
  Title Thick secondary phase pinning-enhanced YBCO films on technical templates Type A1 Journal article
  Year (down) 2018 Publication IEEE transactions on applied superconductivity Abbreviated Journal  
  Volume 28 Issue 4 Pages 8000505  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The critical current I-c(B) of YBa2Cu3O7-delta (YBCO) coated conductors can be increased by growing thicker superconductor layers as well as improving the critical current density J(c)(B) by the incorporation of artificial pinning centers. We studied the properties of pulsed laser deposited BaHfO3 (BHO)-doped YBCO films with thicknesses of up to 5 mu m on buffered rolling-assisted biaxially textured Ni-5 at % W tape and alternating beam assisted deposition textured Yttrium-stabilized ZrO2 layers on stainless steel. X-Ray diffraction confirms the epitaxial growth of the superconductor on the buffered metallic template. BHO additions reduce the film porosity and lower the probability to grow misoriented grains, hence preventing the J(c) decrease observed in undoped YBCO films with thicknesses > 2 mu m. Thereby, a continuous increase in I-c at 77 K is achieved. A mixed structure of secondary phase nanorods and platelets with different orientations increases J(c)(B) in the full angular range and simultaneously lowers the J(c) anisotropy compared to pristine YBCO.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000427623700001 Publication Date 2018-01-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.288 Times cited 1 Open Access Not_Open_Access  
  Notes ; This work was supported by EUROTAPES, a collaborative project funded by the European Commission's Seventh Framework Program (FP7 / 2007 – 2013) under Grant Agreement no. 280432. Max Sieger acknowledges funding by the Graduate Academy of the Technical University Dresden, funded by means of the Excellence Initiative by the German Federal and State Governments. ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:150712 Serial 4986  
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Author Sieger, M.; Pahlke, P.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Ottolinger, R.; Haenisch, J.; Holzapfel, B.; Usoskin, A.; Kursumovic, A.; MacManus-Driscoll, J.L.; Stafford, B.H.; Bauer, M.; Nielsch, K.; Schultz, L.; Huehne, R. url  doi
openurl 
  Title Tailoring microstructure and superconducting properties in thick BaHfO3 and Ba2YNb/Ta)O-6 doped YBCO films on technical templates Type A1 Journal article
  Year (down) 2017 Publication IEEE transactions on applied superconductivity Abbreviated Journal  
  Volume 27 Issue 4 Pages 6601407  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The current transport capability of YBa2Cu3O7-x(YBCO) based coated conductors (CCs) is mainly limited by two features: the grain boundaries of the used textured template, which are transferred into the superconducting film through the buffer layers, and the ability to pin magnetic flux lines by incorporation of defined defects in the crystal lattice. By adjusting the deposition conditions, it is possible to tailor the pinning landscape in doped YBCO in order to meet specific working conditions (T, B) for CC applications. To study these effects, we deposited YBCO layers with a thickness of about 1-2 mu m using pulsed laser deposition on buffered rolling-assisted biaxially textured Ni-W substrates as well as on metal tapes having either an ion-beam-texturedYSZbuffer or an MgO layer textured by inclined substrate deposition. BaHfO3 and the mixed double-perovskite Ba2Y(Nb/Ta)O-6 were incorporated as artificial pinning centers in these YBCO layers. X-ray diffraction confirmed the epitaxial growth of the superconductor on these templates as well as the biaxially oriented incorporation of the secondary phase additions in the YBCO matrix. A critical current density J(c) of more than 2 MA/cm(2) was achieved at 77 K in self-field for 1-2 mu m thick films. Detailed TEM (transmission electron microscopy) studies revealed that the structure of the secondary phase can be tuned, forming c-axis aligned nanocolumns, ab-oriented platelets, or a combination of both. Transport measurements show that the J(c) anisotropy in magnetic fields is reduced by doping and the peak in the J(c) (theta) curves can be correlated to the microstructural features.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000394588100001 Publication Date 2016-12-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 12 Open Access OpenAccess  
  Notes ; This work was supported by EUROTAPES, a collaborative project funded by the European Commission's Seventh Framework Program (FP7/2007-2013) under Grant Agreement no. 280432. ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:141961 Serial 4693  
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Author Sieger, M.; Pahlke, P.; Ottolinger, R.; Stafford, B.H.; Lao, M.; Meledin, A.; Bauer, M.; Eisterer, M.; Van Tendeloo, G.; Schultz, L.; Nielsch, K.; Hühne, R. url  doi
openurl 
  Title Influence of substrate tilt angle on the incorporation of BaHfO3 in thick YBa2Cu3O7-δ films Type A1 Journal article
  Year (down) 2016 Publication IEEE transactions on applied superconductivity Abbreviated Journal  
  Volume 27 Issue 27 Pages 1-4  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High critical current densities can be realized in high-temperature superconductors such as YBa2Cu3O7-δ (YBCO) by controlling density, shape, size and direction of a secondary phase. Whereas the dependence on the growth rate and deposition temperature has been widely studied as key parameters for nano-engineering the pinning landscape, the vicinal tilt of the substrate surface might have an additional influence. Therefore, we deposited 6 mol% BaHfO3 (BHO) doped YBCO on SrTiO3 (STO) substrates with vicinal angles α between 0° and 40° to identify the influence of the tilt on the growth mode of BHO. An undisturbed epitaxial growth of the superconductor as well as an epitaxial integration of the BHO phase in the YBCO matrix is observed for all vicinal angles investigated. The critical temperature is constant up to α = 20°, whereas the self-field critical current density at 77 K starts to decrease above 10°. A detailed structural analysis of the film cross sections showed that the growth mode of BHO changes already for a vicinal tilt of 2° from a pure c-axis oriented growth to a layered structure with BHO aligned parallel to the YBCO ab-plane. We identified a strong influence of such a microstructure on the current flow in BHO doped YBCO films on STO substrates as well as on MgO based coated conductors prepared by inclined substrate deposition  
  Address  
  Corporate Author Thesis  
  Publisher Institute of Electrical and Electronics Engineers (IEEE) Place of Publication Editor  
  Language Wos 000418469400001 Publication Date 2016-11-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 3 Open Access  
  Notes This work was supported by EUROTAPES, a collaborative project funded by the European Commission’s Seventh Framework Program (FP7 / 2007 – 2013) under Grant Agreement n.280432.The authors would like to thank R. Nast, M. Reitner, M. Kühnel, U. Fiedler and J. Scheiter for technical assistance. Approved Most recent IF: NA  
  Call Number EMAT @ emat @ Sieger_2016a c:irua:138603 Serial 4317  
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Author Pahlke, P.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Hanisch, J.; Sieger, M.; Usoskin, A.; Stromer, J.; Holzapfel, B.; Schultz, L.; Huhne, R. pdf  url
doi  openurl
  Title Reduced Anisotropy and Enhanced In-Field Performance of Thick BaHfO3-Doped Films on ABAD-YSZ Templates Type A1 Journal article
  Year (down) 2016 Publication IEEE transactions on applied superconductivity Abbreviated Journal  
  Volume 26 Issue 26 Pages 1-4  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Pure and 6 mol% BaHfO3 (BHO) doped YBa2Cu3O7-δ (YBCO) films were prepared on CeO2-buffered ABAD-YSZ templates by pulsed laser deposition. The self-field Jc at 77 K reaches 1.1 MA/cm² in the doped sample compared to 2.5 MA/cm² in pure YBCO, at a film thickness of around 1 μm. Above a magnetic field of 2.2 T along B||c, Jc of the BHO-doped sample exceeds the Jc of the undoped film. The maximum pinning force density (FP,max) reaches a value of around 3 GN/cm² for both samples, but B(FP,max) increases from 1.4 T (pure) to a value of 2.9 T (BHO:YBCO). The Jc anisotropy curves of the doped sample show a large and broad peak at B||c and a strongly reduced anisotropy at all temperatures and fields compared to the pure sample. A complex defect structure with YBa2Cu4O8 intergrowths, Y2O3 precipitates and BHO nanocolumns with a fanshaped structure is observed by TEM investigations, which can explain the measured Jc(B,θ) behavior.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000376189700001 Publication Date 2016-03-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 14 Open Access  
  Notes This work was supported by EUROTAPES, a collaborative project funded by the European Union’s Seventh Framework Program (FP7 / 2007 – 2013) under Grant Agreement n.280432. Approved Most recent IF: NA  
  Call Number c:irua:133779 Serial 4078  
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Author Sieger, M.; Pahlke, P.; Hanisch, J.; Sparing, M.; Bianchetti, M.; MacManus-Driscoll, J.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Nast, R.; Schultz, L.; Holzapfel, B.; Huhne, R. pdf  url
doi  openurl
  Title Ba2Y(Nb/Ta)O6–Doped YBCO Films on Biaxially Textured Ni–5at.% W Substrates Type A1 Journal article
  Year (down) 2016 Publication IEEE transactions on applied superconductivity Abbreviated Journal  
  Volume 26 Issue 26 Pages 1-5  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The incorporation of nanoscaled pinning centers in superconducting YBa2Cu3O7-d (YBCO) films is one of the core topics to enhance the critical current density Jc(B, Q) of coated conductors. The mixed double-perovskite Ba2Y(Nb/Ta)O6 (BYNTO) can be grown in nanosized columns parallel the YBCO c-axis and in step-like patterns, making it customizable to meet specific working conditions (T, B, Q). We compare a 1.6 μm thick film of pure YBCO and a similar film with additional 5 mol% of BYNTO, grown by pulsed laser deposition with a growth rate of 1.6 nm/s on buffered biaxially textured Ni-5at.% W tape. Our doped sample shows nanosized BYNTO columns parallel cYBCO and plates in the ab-plane containing Y, Nb and Ta. An improved homogeneity of the critical current density Jc over the sample was evaluated from trapped field profiles measured with a scanning Hall probe microscope. The mean Jc in rolling direction of the tape is 1.8 MA/cm² (77 K, self-field) and doubles the value of the undoped sample. Angular dependent measurements of the critical current density, Jc(Q), show a decreased anisotropy of the doped film for various magnetic fields at 77 K as well as 64 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000375581500001 Publication Date 2016-03-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 6 Open Access  
  Notes This work was supported by EUROTAPES, a collaborative project funded by the European Commission’s Seventh Framework Program (FP7 / 2007 – 2013) under Grant Agreement n.280432. Approved Most recent IF: NA  
  Call Number c:irua:133781 Serial 4079  
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Author Lao, M.; Eisterer, M.; Stadel, O.; Meledin, A.; Van Tendeloo, G. url  doi
openurl 
  Title The effect of Y2O3 and YFeO3 additions on the critical current density of YBCO coated conductors Type P1 Proceeding
  Year (down) 2014 Publication 1-4 Abbreviated Journal  
  Volume Issue Pages  
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)  
  Abstract The pinning mechanism of MOCVD-grown YBCO coated conductors with Y2O3 precipitates was investigated by angle-resolved transport measurement of Je in a wide range of temperature and magnetic fields. Aside from the Y2O3 nanoprecipitates, a-axis grains and threading dislocation along the c-axis were found in the YBCO layer. The Y2O3 precipitates are less effective pinning centers at lower temperature. The tapes with precipitates show a higher anisotropy with larger J(c) at H parallel to ab than H parallel to c. This behavior was attributed to the preferred alignment of the nanoprecipitates along the ab-plane.  
  Address  
  Corporate Author Thesis  
  Publisher Iop publishing ltd Place of Publication Bristol Editor  
  Language Wos 000350818300068 Publication Date 2014-05-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 507 Series Issue Edition  
  ISSN 1742-6596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 1 Open Access  
  Notes eurotapes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:125444 Serial 3577  
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