scholarly journals Fabrication by Inclined-Substrate Deposition of Biaxially Textured Buffer Layer for Coated Conductors

2001 ◽  
Vol 689 ◽  
Author(s):  
U. Balachandran ◽  
B. Ma ◽  
M. Li ◽  
R. E. Koritala ◽  
B. L. Fisher ◽  
...  
Keyword(s):  
Coated Conductors ◽  
Buffer Layers ◽  
Laser Deposition ◽  
High Quality ◽  
X Ray ◽  
Roof Tile ◽  
Grain Structures ◽  
Rapid Production ◽  
Columnar Grain ◽  
Ybco Coated Conductors

ABSTRACTInclined substrate deposition (ISD) offers the potential for rapid production of high-quality biaxially textured buffer layers suitable for YBCO-coated conductors. We have grown biaxially textured MgO films by ISD at deposition rates of 20–100 Å/sec. Columnar grain structures with a roof-tile-shaped surface were observed in the ISD-MgO films. X-ray pole figure analysis revealed that the (002) planes of the ISD-MgO films are titled at an angle from the substrate normal. A small phi-scan full-width at half maximum (FWHM) of ≈9° was observed on MgO films deposited at an inclination angle of 55°. YBCO films were also grown on ISD-MgO-buffered Hastelloy C276 substrates by pulsed laser deposition. We obtained a critical current density of ≈2 × 105 A/cm2 at 77 K in self-field on 0.5-μm-thick, 0.5-cm-wide, 1-cm-long samples. This work has demonstrated that biaxially textured ISD MgO buffer layers deposited on metal substrates are promising candidates for fabrication of high-quality YBCO-coated conductors.

Thermoelectric Properties of C-Axis-Oriented Ca3Co4O9+δ Films Grown on MgO-Buffered Si (100) by PLD Technique

2010 ◽  
Vol 29-32 ◽  
pp. 1913-1918
Author(s):  
Xia Zhang ◽  
Hong Chen ◽  
Qiu Hui Liao ◽  
Xia Li
Keyword(s):  
Thin Films ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Buffer Layers ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Current State ◽  
Good Crystallinity

High-quality c-axis-oriented Ca3Co4O9+δ thin films have been grown directly on Si (100) wafers with inserting MgO buffer layers by pulsed-laser deposition (PLD). X-ray diffraction and scan electron microscopy show good crystallinity of the Ca3Co4O9+δ films. The resistivity and Seebeck coefficient of the Ca3Co4O9+δ thin films on Si (100) substrates are 9.8 mΩcm and 189 μV/K at the temperature of 500K, respectively, comparable to the single-crystal samples. This advance demonstrates the possibility of integrating the cobaltate-based high thermoelectric materials with the current state-of-the-art silicon technology for thermoelectricity-on-a-chip applications.

Development of conducting buffer architectures using cube textured IBAD-TiN layers

2008 ◽  
Vol 1150 ◽  
Author(s):  
Ruben Hühne ◽  
Konrad Güth ◽  
Martin Kidszun ◽  
Rainer Kaltofen ◽  
Vladimir Matias ◽  
...  
Keyword(s):  
Ion Beam ◽  
Pulsed Laser ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Laser Deposition ◽  
Tin Films ◽  
Ion Beam Assisted Deposition ◽  
Conductive Oxide ◽  
Ybco Coated Conductors ◽  
Seed Layers

AbstractIon-beam assisted deposition (IBAD) offers the possibility to prepare thin textured films on amorphous or non-textured substrates. In particular, the textured nucleation of TiN is promising for the development of a conducting buffer layer architecture for YBCO coated conductors based on the IBAD approach. Accordingly, cube textured IBAD-TiN layers have been deposited reactively using pulsed laser deposition on Si/Si3N4 substrates as well as on polished Hastelloy tapes using different amorphous seed layers. Metallic buffer layers such as Au, Pt or Ir were grown epitaxially on top of the TiN layer showing texture values similar to the IBAD layer. Smooth layers were obtained using a double layer of Au/Pt or Au/Ir. Biaxially textured YBCO layers were achieved using SrRuO3 or Nb-doped SrTiO3 as a conductive oxide cap layer. Finally, different amorphous conducting seed layers were applied for the IBAD-TiN process. Highly textured TiN films were achieved on amorphous Ta0.75Ni0.25 layers showing a similar in-plane orientation of about 8° as on standard seed layers.

Single buffer layers of LaMnO3 or La0.7Sr0.3MnO3 for the development of Yba2Cu3O7−δ-coated conductors: A comparative study

2002 ◽  
Vol 17 (9) ◽  
pp. 2193-2196 ◽  
Author(s):  
T. Aytug ◽  
M. Paranthaman ◽  
H. H. Zhai ◽  
H. H. Christen ◽  
S. Sathyamurthy ◽  
...  
Keyword(s):  
Superconducting Property ◽  
Pulsed Laser ◽  
Sputter Deposition ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Laser Deposition ◽  
Ybco Films ◽  
Ni Alloy ◽  
Current Densities ◽  
Ybco Coated Conductors

Single, epitaxial buffer layers of insulating LaMnO3 (LMO) or conductive La0.7Sr0.3MnO3 (LSMO) have been grown by sputter deposition on biaxially textured Ni and Ni–alloy substrates. We report baseline investigations of their compatibility with the Yba2Cu3O7−δ (YBCO) coatings and demonstrate biaxially textured YBCO films grown by pulsed-laser deposition on these single-buffered tapes. Superconducting property characterizations revealed better properties for YBCO films on LMO-buffered tapes relative to those grown on LSMO layers. Self-field critical current densities (Jc) exceeding 1 × 106 A/cm2 at 77 K have been obtained for the YBCO (200 nm) films on LMO-buffer layers. These results offer prospects for the use of single, LMO-buffered metal tapes in the development of practical YBCO-coated conductors.

YBa2Cu3O7-y−coated conductors with high engineering current density

2000 ◽  
Vol 15 (12) ◽  
pp. 2647-2652 ◽  
Author(s):  
M. Paranthaman ◽  
C. Park ◽  
X. Cui ◽  
A. Goyal ◽  
D. F. Lee ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Critical Current ◽  
Current Density ◽  
Ybco Film ◽  
Pulsed Laser ◽  
Coated Conductors ◽  
Laser Deposition ◽  
Ex Situ ◽  
Layer Sequence ◽  
Ybco Coated Conductors

Short segments of YBa2Cu3O7-y (YBCO) coated conductors were fabricated on rolling-assisted biaxially textured substrates (RABiTS) with a layer sequence of CeO2/YSZ/Ni using an ex situ BaF2 precursor process. Pulsed laser deposition (PLD) was used to deposit both YSZ and CeO2 layers. The YBCO films were grown using e-beam coevaporated Y–BaF2–Cu precursors followed by postannealing. An overall engineering current density, JE, of 28,000 A/cm2 and critical current, Ic, of 147 A/cm width at 77 K were achieved for a 1.6-μm-thick YBCO film. This result demonstrates the possibility of using both the ex situ BaF2 precursor approach and the RABiTS process for producing long lengths of high-JE coated conductors.

Engineered oxide thin films as 100% lattice match buffer layers for YBCO coated conductors

2003 ◽  
Vol 47 (12) ◽  
pp. 2171-2175 ◽  
Author(s):  
Y. Akin ◽  
Z.K. Heiba ◽  
W. Sigmund ◽  
Y.S. Hascicek
Keyword(s):  
Thin Films ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Oxide Thin Films ◽  
Lattice Match ◽  
Ybco Coated Conductors

Deposition of rare earth tantalate buffers on textured Ni-W substrates for YBCO coated conductor using chemical solution deposition approach

2006 ◽  
Vol 21 (3) ◽  
pp. 767-773 ◽  
Author(s):  
M.S. Bhuiyan ◽  
M. Paranthaman ◽  
A. Goyal ◽  
L. Heatherly ◽  
D.B. Beach
Keyword(s):  
Rare Earth ◽  
Chemical Solution Deposition ◽  
Precursor Solution ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ybco Coated Conductors

Epitaxial films of rare-earth (RE = La, Ce, Eu, and Gd) tantalates, RE3TaO7 with pyrochlore structures were grown on biaxially textured nickel-3 at.% tungsten (Ni-W) substrates using chemical solution deposition (CSD) process. Precursor solution of 0.3∼0.4 M concentration of total cations were spin coated on to short samples of Ni-W substrates and the films were crystallized at 1050∼1100 °C in a gas mixture of Ar- 4% H2 for 15 to 60 min. X-ray studies show that the films of pyrochlore RE tantalate films are highly textured with cube-on-cube epitaxy. Improved texture was observed in case of lanthanum tantalate (La3TaO7) film grown on Ni-W substrates. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) investigations of RE3TaO7 films reveal a fairly dense and smooth microstructure without cracks and porosity. The rare-earth tantalate layers may be potentially used as buffer layers for YBa2Cu3O7-δ (YBCO) coated conductors.

scholarly journals Cubic InGaN Grown by MOCVD

1999 ◽  
Vol 4 (S1) ◽  
pp. 239-243
Author(s):  
J.B. Li ◽  
Hui Yang ◽  
L.X. Zheng ◽  
D.P. Xu ◽  
Y.T. Wang
Keyword(s):  
Room Temperature ◽  
Emission Peak ◽  
Buffer Layers ◽  
Cubic Phase ◽  
Yellow Luminescence ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Cubic Gan ◽  
Pl Emission

We report on the growth of high-quality cubic phase InGaN on GaAs by MOCVD. The cubic InGaN layers are grown on cubic GaN buffer layers on GaAs (001) substrates. The surface morphology of the films are mirror-like. The cubic nature of the InGaN films is obtained by X-ray diffraction (XRD) measurements. The InGaN layers show strong photoluminescence (PL) at room temperature. Neither emission peak from wurtzite GaN nor yellow luminescence is observed in our films. The highest In content as determined by XRD is about 17% with an PL emission wavelength of 450 nm. The FWHM of the cubic InGaN PL peak are 153 meV and 216 meV for 427 nm and 450 nm emissions, respectively. It is found that the In compositions determined from XRD are not in agreement with those estimated from PL measurements. The reasons for this disagreement are discussed.

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