Aqueous Chemical Solution Deposition of Novel, Thick and Dense Lattice-Matched Single Buffer Layers Suitable for YBCO Coated Conductors: Preparation and Characterization
In this work we present the preparation and characterization of cerium doped lanthanum zirconate (LCZO) films and non-stoichiometric lanthanum zirconate (LZO) buffer layers on metallic Ni-5% W substrates using chemical solution deposition (CSD), starting from aqueous precursor solutions. La 2Zr 2O 7 films doped with varying percentages of Ce at constant La concentration (La 0.5Ce xZr 1？xO y) were prepared as well as non-stoichiometric La 0.5+xZr 0.5？xO y buffer layers with different percentages of La and Zr ratios. The variation in the composition of these thin films enables the creation of novel buffer layers with tailored lattice parameters. This leads to different lattice mismatches with the YBa 2Cu 3O 7？x (YBCO) superconducting layer on top and with the buffer layers or substrate underneath. This possibility of minimized lattice mismatch should allow the use of one single buffer layer instead of the current complicated buffer architectures such as Ni-(5% W)/LZO/LZO/CeO 2. Here, single, crack-free LCZO and non-stoichiometric LZO layers with thicknesses of up to 140 nm could be obtained in one single CSD step. The crystallinity and microstructure of these layers were studied by XRD, and SEM and the effective buffer layer action was studied using XPS depth profiling.
References
[1]
Goyal, A.; Norton, D.P.; Christen, D.K.; Specht, E.D.; Paranthaman, M.; Kroeger, D.M.; Budai, J.D.; He, Q.; List, F.A.; Feenstra, R.; et al. Epitaxial superconductors on rolling-assisted biaxially-textured substrates (RABiTS): A route towards high critical current density wire. Appl. Supercond. 1996, 61, 403–427.
[2]
Cloet, V.; Feys, J.; Hühne, R.; Hoste, S.; van Driessche, I. Thin La2Zr2O7 ？lms made from a water-based solution. J. Solid State Chem. 2009, 182, 37–42.
[3]
Knoth, K.; Hühne, R.; Oswald, S.; Schultz, L.; Holzapfel, B. Detailed investigations on La2Zr2O7 buffer layers for YBCO-coated conductors prepared by chemical solution deposition. Acta Mater. 2007, 55, 517–529.
[4]
Knoth, K.; Schlobach, B.; Hühne, R.; Schultz, L.; Holzapfel, B. La2Zr2O7 and Ce-Gd-O buffer layers for YBCO coated conductors using chemical solution deposition. Phys. C 2005, 426, 979–984, doi:10.1016/j.physc.2005.03.077.
[5]
Narayanan, V.; Lommens, P.; de Buysser, K.; Hühne, R.; van Driessche, I. Thick lanthanum zirconate buffer layers from water-based precursor solutions on Ni-5% W substrates. J. Solid State Chem. 2011, 184, 2887–2896, doi:10.1016/j.jssc.2011.08.035.
[6]
Sathyamurthy, S.; Paranthaman, M.; Heatherly, L.; Martin, P.M.; Specht, E.D.; Goyal, A.; Kodenkandath, T.; Li, X.; Rupich, M.W. Solution-processed lanthanum zirconium oxide as a barrier layer for high Ic-coated conductors. J. Mater. Res. 2006, 21, 910–914.
[7]
Van de Velde, N.; van de Vyver, D.; Brunkahl, O.; Hoste, S.; Bruneel, E.; van Driessche, I. CeO2 buffer layers for HTSC by an aqueous sol-gel method—Chemistry and microstructure. Eur. J. Inorg. Chem. 2010, 2010, 233–241.
[8]
Thuy, T.T.; Lommens, P.; Narayanan, V.; van de Velde, N.; de Buysser, K.; Herman, G.G.; Cloet, V. A nitrilo-tri-acetic-acid/acetic acid route for the deposition of epitaxial cerium oxide films as high temperature superconductor buffer layers. J. Solid State Chem. 2010, 183, 2154–2160, doi:10.1016/j.jssc.2010.07.009.
[9]
Coll, M.; Gazquez, J.; Hühne, R.; Holzapfel, B.; Morilla, Y.; Garcia-Lopez, J.; Pomar, A.; Sandiumenge, F.; Puig, T.; Obradors, X. All chemical YBa2Cu3O7 superconducting multilayers: Critical role of CeO2 cap layer flatness. J. Mater. Res. 2009, 24, 1446–1455.
[10]
Engel, S.; Knoth, K.; Hühne, R.; Schultz, L.; Holzapfel, B. An all chemical solution deposition approach for the growth of highly textured CeO2 cap layers on La2Zr2O7-buffered long lengths of biaxially textured Ni-W substrates for YBCO-coated conductors. Supercond. Sci. Technol. 2005, 18, 1385–1390, doi:10.1088/0953-2048/18/10/024.
[11]
Zhou, Y.X.; Zhang, X.; Fang, H.; Putman, P.T.; Salama, K. Development of single solution buffer layers on textured Ni substrate for HTS coated conductors. IEEE Trans. Appl. Supercond. 2005, 15, 2711–2714.
Akin, Y.; Heiba, Z.K.; Sigmund, W.; Hascicek, Y.S. Engineered oxide thin films as 100% lattice match buffer layers for YBCO coated conductors. Solid State Electron. 2003, 47, 2171–2175, doi:10.1016/S0038-1101(03)00192-8.
[14]
Narayanan, V.; Lommens, P.; de Buysser, K.; Hühne, R.; Vanpoucke, D.; Molina, L.; van Tendeloo, G.; van der Voort, P.; van Driessche, I. Aqueous CSD approach for the growth of novel, lattice-tuned LaxCe1？xOδ epitaxial layers. J. Mater. Chem. 2012, 22, 8476–8483.
[15]
Yue, Z.; Li, X.; Khoryushin, A.; He, D.; Andersen, N.H.; Hansen, J.B.; Grivel, J. Development of all chemical solution derived Ce0.9La0.1O2？y/GdcZrcO7 buffer layer stack for coated conductors: Influence of the post-annealing process on surface crystallinity. Supercond. Sci. Technol. 2012, 25, 015008, doi:10.1088/0953-2048/25/1/015008.
[16]
Li, G.; Pu, M.H.; Du, X.H.; Sun, R.P.; Zhang, H.; Zhao, Y. Deposition of potential Y2？xBixO3 buffer layers for YBCO coated conductor. Phys. C 2007, 463, 589–593.
[17]
Arda, L.; Heiba, Z.K. Rare-earth mixed oxide thin films as 100% lattice match buffer layers for YBa2Cu3O7？x coated conductors. Thin Solid Films 2010, 518, 3345–3350, doi:10.1016/j.tsf.2010.01.002.
[18]
Paranthaman, M.P.; Qiu, X.; List, F.A.; Kim, K.; Zhang, Y.; Li, X.; Sathyamurthy, S.; Thieme, C.; Rupich, M.W. Development of solution buffer layers for RABiTS based YBCO coated conductors. IEEE Trans. Appl. Supercond. 2011, 21, 3059–3061.
[19]
Bhuiyan, M.S.; Paranthaman, M.; Salama, K. Solution-derived textured oxide thin films—A review. Supercond. Sci. Technol. 2006, 19, R1–R21, doi:10.1088/0953-2048/19/2/R01.
[20]
Van Driessche, I.; Penneman, G.; Bruneel, E.; Hoste, S. Non vacuum-based deposition techniques for superconducting ceramic coatings. Pure Appl. Chem. 2002, 74, 2101–2109, doi:10.1351/pac200274112101.
[21]
Zhou, H.; Yi, D. Effect of rare earth doping on thermo-physical properties of lanthanum zirconate ceramic for thermal barrier coatings. J. Rare Earths 2008, 26, 770–774, doi:10.1016/S1002-0721(09)60002-8.
[22]
Yi, G.; Sayer, M. An acetic acid/water based sol-gel PZT process I: Modification of Zr and Ti alkoxides with acetic acid. J. Sol-Gel Sci. Technol. 1996, 6, 65–74, doi:10.1007/BF00402590.
[23]
Martell, A.E.; Smith, R.M. Critical Stability Constants; Plenum press: New York, NY, USA, 1975.
[24]
Kozuka, H.; Higuchi, A. Single-layer submicron-thick BaTiO3 coatings from poly(vinylpyrrolidone)-containing sols: Gel-to-ceramic film conversion, densification, and dielectric properties. J. Mater. Res. 2001, 16, 3116–3123, doi:10.1557/JMR.2001.0430.
[25]
Horcas, I.; Fernández, R.; Gómez-Rodríguez, J.M.; Colchero, J.; Gómez-Herrero, J.; Baro, A.M. WSXM: A software for scanning probe microscopy and a tool for nanotechnology. Rev. Sci. Instrum. 2007, 78, 013705:1–013705:8.
[26]
Narayanan, V.; de Buysser, K.; Bruneel, E.; van Driessche, I. X-ray photoelectron spectroscopy (XPS) depth profiling for evaluation of La2Zr2O7 buffer layer capacity. Materials 2012, 5, 364–376, doi:10.3390/ma5030364.
