Comparison of Several CU(I) and CU(II) Precursors for the Sol-Gel Preparation of High TC Superconducting Metal Oxides

1988 ◽  
Vol 121 ◽  
Author(s):  
Mariquita A. Accibal ◽  
Jonathan W. Draxton ◽  
Allen H. Gabor ◽  
Wayne L. Gladfelter ◽  
Beth Anne Hassler ◽  
...  
Keyword(s):  
Thin Films ◽  
Metal Oxides ◽  
Coordination Compounds ◽  
Sol Gel ◽  
High Tc ◽  
Superconducting Metal ◽  
Zero Resistance ◽  
Gel Preparation ◽  
Sol Gel Synthesis

ABSTRACTA comparison of the use of three different coordination compounds of copper as precursors for the sol-gel synthesis of YBa2Cu3O7-δ has been made. For yttrium, the tris(isopropoxide) was used exclusively, while the use of both Ba(O-i-Pr)2 and Ba(OCH2CH2OEt)2 (prepared in situ from Ba metal) as sources for Ba were studied. After dissolving Y(O-i-pr)3, a Ba source, and the copper(I) alkoxide, [Cu(O-i-Bu)]4, hydrolysis led immediately to an orange gelatinous solid which yielded YBa2Cu3O7-δ upon firing in oxygen. Copper(II) acetate was found to give heterogeneous mixtures under our conditions and was not further studied. Copper(II) acac (acac = acetylacetonate) yielded the best results. Partially hydrolyzed solutions of Cu(acac)2, Ba(OCH2CH2OEt)2, and Y(O-i-pr)3 were spin coated on SrTi03 (100) and fired under oxygen to give oriented (b axis normal to the surface) thin films of YBa2Cu3O7-δ. The onset of superconductivity for the films was 92 K, but they did not reach zero resistance until much lower temperatures.

In-Situ Processing of Epitaxial and Textured High Tc Superconducting Hoba2Cu3O7.X Thin Films By Pulsed Laser Evaporation Technique

1989 ◽  
Vol 169 ◽  
Author(s):  
C. B. Lee ◽  
R. Prasad ◽  
A. K. Singh ◽  
S. Sharan ◽  
R. K. Singh ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Laser Evaporation ◽  
High Tc ◽  
Zero Resistance ◽  
Evaporation Technique ◽  
Current Densities ◽  
Lattice Matched

AbstractExcellent quality epitaxial and textured superconducting HoBa2Cu307.x (Ho 123) thin films have been fabricated on lattice matched (100) KTaO3 and (100) LaAlO3, and lattice mismatched (100) MgO substrates by the pulsed laser evaporation (PLE) technique. A bulk Hol23 target was evaporated using nanosecond excimer laser pulses with the evaporating material depositing on a substrate maintained in the temperature range of 550‐650°C. The temperature for zero resistance for HoBa2Cu3O7_x films deposited on various substrates at 650°C varied between 85 to 89K. The epitaxial films deposited on (100) LaA103 substrates exhibited critical current densities greater than 3.5 x 106 Amps/cm2 at 77 K. The superconducting properties of the Ho 123 films were found to be similar to Y123 films.

Sol-gel synthesis of textured lanthanum titanate thin films

2003 ◽  
Vol 18 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Mary M. Sandstrom ◽  
Paul Fuierer
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Precursor Solution ◽  
Solution Concentration ◽  
Optical Measurements ◽  
Layered Perovskite ◽  
Orientation Factor ◽  
Anisotropic Structures ◽  
Sol Gel Films ◽  
Sol Gel Synthesis

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.

Sol–gel synthesis and photoluminescent properties of LaPO4:A (A = Eu3+, Ce3+, Tb3+) nanocrystalline thin films

2003 ◽  
Vol 13 (6) ◽  
pp. 1413-1419 ◽  
Author(s):  
M. Yu ◽  
J. Lin ◽  
J. Fu ◽  
H. J. Zhang ◽  
Y. C. Han
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Sol Gel Synthesis ◽  
Nanocrystalline Thin Films

Upconverting Er3+,Yb3+ activated β-NaYF4 thin films: a solution route using a novel sodium β-diketonate polyether adduct

2017 ◽  
Vol 41 (12) ◽  
pp. 4771-4775 ◽  
Author(s):  
Maria R. Catalano ◽  
Anna L. Pellegrino ◽  
Patrizia Rossi ◽  
Paola Paoli ◽  
Paolo Cortelletti ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Solution Route ◽  
Sol Gel Synthesis

A new Na(hfa)·tetraglyme adduct has been synthesized and successfully applied, together with the RE(hfa)3·diglyme (RE = Y, Yb, Er) complexes, in the sol–gel synthesis of upconverting hexagonal NaYF4:Yb3+,Er3+ films.

Chemical Analyses of Sol/Gel Surfaces and Thin Films

1984 ◽  
Vol 32 ◽  
Author(s):  
Carlo G. Pantano ◽  
C. A. Houser ◽  
R. K. Brow
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Films ◽  
Alumina Films ◽  
Surface Analysis Techniques ◽  
Relative Water ◽  
Temperature Programmed

ABSTRACTThe application of surface analysis techniques to the characterization of sol/gel surfaces and thin films is described. Secondary-ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS) and sputter-induced photon spectroscopy (SIPS) are used to measure the composition of multicomponent silicate films, the relative water content of alumina films, the nitrogen content of ammonia treated silica films, and the depth profiles for films on black chrome. The determination of chemical structure using XPS and SIMS is also discussed. Finally, a brief introduction to temperature-programmed desorption (TPD) and its potential for studying surface chemical reactions, in situ, is presented.

In-Situ Laser Processing and Microstructural Characteristics of YBa2Cu3O7−δ Thin Films on Si with TiN Buffer Layer

1992 ◽  
Vol 285 ◽  
Author(s):  
P. Tiwari ◽  
T. Zheleva ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transition Temperature ◽  
Buffer Layer ◽  
Processing Parameters ◽  
Superconducting Transition ◽  
Epitaxial Relationship ◽  
Ybco Thin Films ◽  
Zero Resistance

ABSTRACTWe have prepared high-quality superconducting YBa2Cu3O7−δ (YBCO) thin films on Si(100) with TiN as a buffer layer using in-situ multitarget deposition system. Both TiN and YBCO thin films were deposited sequentially by KrF excitner laser ( λ = 248 nm ) at substrate temperature of 650°C. Thin films were characterized using X-ray diffraction (XRD), four-point-probe ac resistivity, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Rutherford backscattering (RBS). The TiN buffer layer was epitaxial and the epitaxial relationship was found to be cube on cube with <100> TiN // <100> Si. YBCO thin films on Si with TiN buffer layer showed the transition temperature of 90–92K with Tco (zero resistance temperature) of ∼84K. We have found that the quality of the buffer layer is very important in determining the superconducting transition temperature of the thin film. The effects of processing parameters and the correlation of microstructural features with superconducting properties are discussed indetail.

Mo-doped BiVO4 thin films – high photoelectrochemical water splitting performance achieved by a tailored structure and morphology

2017 ◽  
Vol 1 (8) ◽  
pp. 1830-1846 ◽  
Author(s):  
Martin Rohloff ◽  
Björn Anke ◽  
Siyuan Zhang ◽  
Ulrich Gernert ◽  
Christina Scheu ◽  
...  
Keyword(s):  
Thin Films ◽  
Water Splitting ◽  
Sol Gel ◽  
Surface Recombination ◽  
Photoelectrochemical Water Splitting ◽  
Transfer Efficiency ◽  
Hole Transfer ◽  
Structure And Morphology ◽  
Sol Gel Synthesis ◽  
Reduced Surface

Facile sol–gel synthesis of Mo:BiVO4 thin films with optimized morphology results in reduced surface recombination and enhanced hole transfer efficiency.

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