| |
Records |
Links |
|
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. |
|
| |
Title |
Influence of substrate tilt angle on the incorporation of BaHfO3 in thick YBa2Cu3O7-δ films |
Type |
A1 Journal article |
| |
Year  |
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 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Opherden, L.; Sieger, M.; Pahlke, P.; Hühne, R.; Schultz, L.; Meledin, A.; Van Tendeloo, G.; Nast, R.; Holzapfel, B.; Bianchetti, M.; MacManus-Driscoll, J.L.; Hänisch, J. |
|
| |
Title |
Large pinning forces and matching effects in YBa2Cu3O7-δ thin films with Ba2Y(Nb/Ta)O6 nano-precipitates |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
21188 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The addition of mixed double perovskite Ba2Y(Nb/Ta)O6 (BYNTO) to YBa2Cu3O7−δ (YBCO) thin films leads to a large improvement of the in-field current carrying capability. For low deposition rates, BYNTO grows as well-oriented, densely distributed nanocolumns. We achieved a pinning force density of 25 GN/m3 at 77 K at a matching field of 2.3 T, which is among the highest values reported for YBCO. The anisotropy of the critical current density shows a complex behavior whereby additional maxima are developed at field dependent angles. This is caused by a matching effect of the magnetic fields c-axis component. The exponent N of the current-voltage characteristics (inversely proportional to the creep rate S) allows the depinning mechanism to be determined. It changes from a double-kink excitation below the matching field to pinning-potential-determined creep above it. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000370364500001 |
Publication Date |
2016-02-18 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.259 |
Times cited |
39 |
Open Access |
|
|
| |
Notes |
The authors gratefully acknowledge J. Scheiter, U. Besold, and U. Fiedler for technical assistance. This work was financially 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: 4.259 |
|
| |
Call Number |
c:irua:131920 |
Serial |
4026 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Erbe, M.; Hänisch, J.; Hühne, R.; Freudenberg, T.; Kirchner, A.; Molina-Luna, L.; Damm, C.; Van Tendeloo, G.; Kaskel, S.; Schultz, L.; Holzapfel, B. |
|
| |
Title |
BaHfO3artificial pinning centres in TFA-MOD-derived YBCO and GdBCO thin films |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
| |
Volume |
28 |
Issue |
28 |
Pages |
114002 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Chemical solution deposition (CSD) is a promising way to realize REBa2Cu3O7−x (REBCO;RE = rare earth (here Y, Gd))-coated conductors with high performance in applied magnetic fields. However, the preparation process contains numerous parameters which need to be tuned to achieve high-quality films. Therefore, we investigated the growth of REBCO thin films containing nanometre-scale BaHfO3 (BHO) particles as pinning centres for magnetic flux lines, with emphasis on the influence of crystallization temperature and substrate on the microstructure and superconductivity. Conductivity, microscopy and x-ray investigations show an enhanced performance of BHO nano-composites in comparison to pristine REBCO. Further, those measurements reveal the superiority of GdBCO to YBCO—e.g. by inductive critical current densities, Jc, at self-field and 77 K. YBCO is outperformed by more than 1 MA cm−2 with Jc values of up to 5.0 MA cm−2 for 265 nm thick layers of GdBCO(BHO) on lanthanum aluminate. Transport in-field Jc measurements demonstrate high pinning force maxima of around 4 GN m−3 for YBCO(BHO) and GdBCO(BHO). However, the irreversibility fields are appreciably higher for GdBCO. The critical temperature was not significantly reduced upon BHO addition to both YBCO and GdBCO, indicating a low tendency for Hf diffusion into the REBCO matrix. Angular-dependent Jc measurements show a reduction of the anisotropy in the same order of magnitude for both REBCO compounds. Theoretical models suggest that more than one sort of pinning centre is active in all CSD films. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000366193000003 |
Publication Date |
2015-09-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.878 |
Times cited |
36 |
Open Access |
|
|
| |
Notes |
Experimental work was mainly done at IFW Dresden. We thank Juliane Scheiter and Dr Jens Ingolf Mönch of IFW Dresden for technical assistance. The research leading to these results received funding from EUROTAPES, a collaborative project funded by the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. NMP-LA-2012-280 432. L Molina-Luna and G Van Tendeloo acknowledge funding from the European Research Council (ERC grant nr. 24 691-COUNTATOMS). |
Approved |
Most recent IF: 2.878; 2015 IF: 2.325 |
|
| |
Call Number |
c:irua:129200 |
Serial |
3941 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Pollefeyt, G.; Meledin, A.; Pop, C.; Ricart, S.; Hühne, R.; Van Tendeloo, G.; Van Driessche, I. |
|
| |
Title |
Chemical stability of YBiO3 buffer layers for implementation in YBa2Cu3O7-δ coated conductors |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
100 |
Issue |
100 |
Pages |
224-231 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
In this work, the chemical and microstructural stability of YBiO3 buffer layers during the growth of YBa2Cu3O7-δ (YBCO) was studied. The superconducting YBCO films were deposited via both Pulsed Laser Deposition as well as Chemical Solution Deposition. Although excellent superconducting properties are obtained in both cases, self-field critical current densities of 3.6 and 1.2 MA/cm2 respectively, chemical instability of the YBiO3 buffer layer is observed. An elaborate transmission electron microscopy study showed that in the case of vacuum deposited YBCO, the YBiO3 becomes unstable and Bi2O3 sublimates out of the architecture. Due to this structural instability, an intermediate Y2O3 layer is obtained which maintains it microstructural orientation relation with the substrate and acts as growth template for YBCO. For chemical solution deposited YBCO, reaction of YBCO with the YBiO3 buffer layer is observed, leading to large grains of YBa2BiO6 which are pushed towards the surface of the films and strongly reduce the superconducting properties. Upon using high growth temperatures for the superconducting layer, these secondary phases decompose, which subsequently leads to Bi2O3 sublimation and a textured YBCO film which directly nucleated onto the LaAlO3 single crystal substrate. Hence, this electron microscopy study indicates that bismuth-based buffer layers systems are not suitable for implementation in coated conductors. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000362616400023 |
Publication Date |
2015-08-29 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
5.301 |
Times cited |
|
Open Access |
|
|
| |
Notes |
One of the authors (G.P.) would like to thank the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT) for funding. Part of this work was performed within the framework of the EuroTapes project (FP7-NMP.2011.2.2-1 Grant No. 280438), funded by the European Union. |
Approved |
Most recent IF: 5.301; 2015 IF: 4.465 |
|
| |
Call Number |
c:irua:128757 |
Serial |
3953 |
|
| Permanent link to this record |
