|   | 
Details
   web
Records
Author Molina, L.; Egoavil, R.; Turner, S.; Thersleff, T.; Verbeeck, J.; Holzapfel, B.; Eibl, O.; Van Tendeloo, G.
Title Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition Type A1 Journal article
Year (down) 2013 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 26 Issue 7 Pages 075016-75018
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000319973800024 Publication Date 2013-05-28
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 11 Open Access
Notes vortex; Countatoms; Fwo; Esteem2; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 2.878; 2013 IF: 2.796
Call Number UA @ lucian @ c:irua:108704UA @ admin @ c:irua:108704 Serial 1698
Permanent link to this record
 

 
Author Narayanan, V.; Lommens, P.; De Buysser, K.; Vanpoucke, D.E.P.; Huehne, R.; Molina, L.; Van Tendeloo, G.; van der Voort, P.; Van Driessche, I.
Title Aqueous CSD approach for the growth of novel, lattice-tuned LaxCe1-xO\delta epitaxial layers Type A1 Journal article
Year (down) 2012 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 22 Issue 17 Pages 8476-8483
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Lanthanumcerium oxide (LCO) films were deposited on Ni-5%W substrates by chemical solution deposition (CSD) from water-based precursors. LCO films containing different ratios of lanthanum and cerium ions (from CeO2 to La2Ce2O7) were prepared. The composition of the layers was optimized towards the formation of LCO buffer layers, lattice-matched with the superconducting YBa2Cu3Oy layer, useful for the development of coated conductors. Single, crack-free LCO layers with a thickness of up to 140 nm could be obtained in a single deposition step. The crystallinity and microstructure of these lattice-matched LCO layers were studied by X-ray diffraction techniques, RHEED and SEM. We find that only layers with thickness below 100 nm show a crystalline top surface although both thick and thin layers show good biaxial texture in XRD. On the most promising layers, AFM and (S)TEM were performed to further evaluate their morphology. The overall surface roughness varies between 3.9 and 7.5 nm, while the layers appear much more dense than the frequently used La2Zr2O7 (LZO) systems, showing much smaller nanovoids (12 nm) than the latter system. Their effective buffer layer action was studied using XPS. The thin LCO layers supported the growth of superconducting YBCO deposited using PLD methods.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000302367500044 Publication Date 2012-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 24 Open Access
Notes Iap Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:96960 Serial 148
Permanent link to this record
 

 
Author Molina, L.; Tan, H.; Biermans, E.; Batenburg, K.J.; Verbeeck, J.; Bals, S.; Van Tendeloo, G.
Title Barrier efficiency of sponge-like La2Zr2O7 buffer layers for YBCO-coated conductors Type A1 Journal article
Year (down) 2011 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 24 Issue 6 Pages 065019-065019,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Solution derived La2Zr2O7 films have drawn much attention for potential applications as thermal barriers or low-cost buffer layers for coated conductor technology. Annealing and coating parameters strongly affect the microstructure of La2Zr2O7, but different film processing methods can yield similar microstructural features such as nanovoids and nanometer-sized La2Zr2O7 grains. Nanoporosity is a typical feature found in such films and the implications for the functionality of the films are investigated by a combination of scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS) and quantitative electron tomography. Chemical solution based La2Zr2O7 films deposited on flexible Ni5 at.%W substrates with a {100}lang001rang biaxial texture were prepared for an in-depth characterization. A sponge-like structure composed of nanometer-sized voids is revealed by high-angle annular dark-field scanning transmission electron microscopy in combination with electron tomography. A three-dimensional quantification of nanovoids in the La2Zr2O7 film is obtained on a local scale. Mostly non-interconnected highly faceted nanovoids compromise more than one-fifth of the investigated sample volume. The diffusion barrier efficiency of a 170 nm thick La2Zr2O7 film is investigated by STEM-EELS, yielding a 1.8 ± 0.2 nm oxide layer beyond which no significant nickel diffusion can be detected and intermixing is observed. This is of particular significance for the functionality of YBa2Cu3O7 − δ coated conductor architectures based on solution derived La2Zr2O7 films as diffusion barriers.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000290472900021 Publication Date 2011-04-20
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 31 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 2.878; 2011 IF: 2.662
Call Number UA @ lucian @ c:irua:88639UA @ admin @ c:irua:88639 Serial 221
Permanent link to this record
 

 
Author Biermans, E.; Molina, L.; Batenburg, K.J.; Bals, S.; Van Tendeloo, G.
Title Measuring porosity at the nanoscale by quantitative electron tomography Type A1 Journal article
Year (down) 2010 Publication Nano letters Abbreviated Journal Nano Lett
Volume 10 Issue 12 Pages 5014-5019
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Quantitative electron tomography is proposed to characterize porous materials at a nanoscale. To achieve reliable three-dimensional (3D) quantitative information, the influence of missing wedge artifacts and segmentation methods is investigated. We are presenting the Discrete Algebraic Reconstruction Algorithm as the most adequate tomography method to measure porosity at the nanoscale. It provides accurate 3D quantitative information, regardless the presence of a missing wedge. As an example, we applied our approach to nanovoids in La2Zr2O7 thin films.
Address
Corporate Author Thesis
Publisher Place of Publication Washington Editor
Language Wos 000284990900040 Publication Date 2010-11-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984;1530-6992; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited 79 Open Access
Notes Esteem 026019 Approved Most recent IF: 12.712; 2010 IF: 12.219
Call Number UA @ lucian @ c:irua:87658 Serial 1967
Permanent link to this record