Epitaxial Growth of Cerium Oxide Buffer Layers on MgO, YSZ and Sapphire Substrates

2000 ◽  
Vol 619 ◽  
Author(s):  
A. Thorley ◽  
S. Gnanarajan ◽  
A. Katsaros ◽  
N. Savvides
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Buffer Layers ◽  
Metal Target ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
X Ray ◽  
Sapphire Substrates ◽  
Pole Figures ◽  
Biaxial Alignment

ABSTRACTWe studied the epitaxial growth of CeO2 thin films deposited onto MgO(100), YSZ(100) and Al2O3(1102 ) (r-plane sapphire) substrates by reactive dc magnetron sputtering of a Ce metal target in an Ar/O2 plasma. The crystalline quality and biaxial alignment of the films was determined using x-ray diffraction techniques (θ-2θ, ω-scans, pole figures, ø-scans). The CeO2/MgO(100) and CeO2/Al2O3(1102) epitaxy was evident at 600°C and developed to nearly perfect biaxial alignment at 850°C with Δø = 5° and 9° respectively. The CeO2/YSZ (100) epitaxy occurred below 300°C while deposition at ≥ 650°C led to single-crystal quality CeO2 films with Δø = 0.2°.

The Use of BaF2 Buffer Layers for the Sputter-Deposition of Ticabacuo Thin-Film Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
K.M. Hubbard ◽  
P.N. Arendt ◽  
D.R. Brown ◽  
D.W. Cooke ◽  
N.E. Elliott ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Sputter Deposition ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
X Ray ◽  
Film Substrate ◽  
Ion Backscattering ◽  
Scanning Electron

AbstractThin films of the Tl‐based superconductors often have relatively poor properties because of film/substrate interdiffusion which occurs during the anneal. We have therefore investigated the use of BaF2 as a diffusion barrier. TICaBaCuO thin films were deposited by dc magnetron sputtering onto MgO <100> substrates, both with and without an evaporation‐deposited BaF2 buffer layer, and post‐annealed in a Tl over‐pressure. Electrical properties of the films were determined by four‐point probe analysis, and compositions were measured by ion‐backscattering spectroscopy. Structural analysis was performed by X‐ray diffraction and scanning electron microscopy. The BaF2 buffer layers were found to significantly improve the properties of the TICaBaCuO thin films.

Epitaxial Buffer Layers on (012) Sapphire and (100) SrTiO3 for the Integration of YBa2Cu3Ox in Microwave Devices and Squids

1992 ◽  
Vol 275 ◽  
Author(s):  
H. Schmidt ◽  
G. Vollnhals ◽  
G. Gieres ◽  
W. Wersing ◽  
H. Kinder
Keyword(s):  
Grain Boundaries ◽  
Epitaxial Growth ◽  
Pole Figure ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layer Sequence ◽  
Ion Channeling ◽  
Sapphire Substrates ◽  
Microwave Applications

ABSTRACTThe epitaxial growth of YBa2Cu3Ox films on sapphire for microwave applications requires epitaxial buffer layers hindering interdiffusion. Therefore the epitaxial growth of YSZ, the layer sequence Y2O3/YSZ, and Y2O3 on (012) sapphire was examined. In addition the growth of MgO and srTiO3 on sapphire substrates and the growth of MgO and CeO2 on SrTiO3 substrates was studied by X-ray diffraction, X-ray pole figure measurement and RBS-ion channeling. With a combination of these buffer layers bi-epitaxial grain boundaries in YBa2Cu3Ox films can be fabricated in future.

Effect of Growth Conditions and Buffer Layers on the Metal-Insulator Transition in V2O3 Thin Films

1995 ◽  
Vol 401 ◽  
Author(s):  
H. Schuler ◽  
G. Weissmann ◽  
C. Renner ◽  
S. Six ◽  
S. Klimm ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Conditions ◽  
Buffer Layers ◽  
Infrared Transmission ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray ◽  
Sapphire Substrates ◽  
Hall Effect Measurements ◽  
Mi Transition

AbstractThin films of V2O3 with thickness from 20 to 450 nm were deposited on (0001) oriented sapphire substrates by reactive e-beam evaporation. LEED, x-ray diffraction and AFM studies show highly oriented grains with a lateral size of 50 to 800 nm, dependent on substrate temperature and deposition rate. The films were characterized by optical and infrared transmission, electrical resistance and Hall effect measurements. Films grown directly on the Al2O3-substrate show a very broad metal-insulator (MI) transition as a function of temperature. The width of the transition decreases with increasing film thickness. The insertion of Cr2O3 buffer layers decreases the transition width by a further factor of three. The electronic properties of the films can be drastically influenced by the growth conditions.

Transparent Conductive Cu-In-O Thin Films Deposited by Reactive DC Magnetron Sputtering with Different Targets

2011 ◽  
Vol 239-242 ◽  
pp. 2752-2755
Author(s):  
Fan Ye ◽  
Xing Min Cai ◽  
Fu Ping Dai ◽  
Dong Ping Zhang ◽  
Ping Fan ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Optical Band Gap ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
Equal Distance ◽  
Transmittance Curve

Transparent conductive Cu-In-O thin films were deposited by reactive DC magnetron sputtering. Two types of targets were used. The first was In target covered with a fan-shaped Cu plate of the same radius and the second was Cu target on which six In grains of 1.5mm was placed with equal distance between each other. The samples were characterized with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV/VIS spectrophotometer, four-probe measurement etc. SEM shows that the surfaces of all the samples are very smooth. EDX shows that the samples contain Cu, In as well as O, and different targets result in different atomic ratios of Cu to In. A diffraction peak related to rhombohedra-centered In2O3(012) is observed in the XRD spectra of all the samples. For both the two targets, the transmittance decreases with the increase of O2flow rates. The direct optical band gap of all the samples is also estimated according to the transmittance curve. For both the two targets, different O2flow rates result in different sheet resistances and conductivities. The target of Cu on In shows more controllability in the composition and properties of Cu-In-O films.

MICROSTRUCTURES OF SPUTTERED ORIENTED Si/CeO2 BILAYERs YBa2Cu3O7-δ/Si INTEGRATED MICROELECTRONICS

2003 ◽  
Vol 17 (04n06) ◽  
pp. 848-854 ◽  
Author(s):  
A. CHIODONI ◽  
E. MEZZETTI ◽  
D. BOTTA ◽  
L. GOZZELINO ◽  
B. MINETTI ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Cerium Dioxide ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Sputtering Deposition ◽  
X Ray ◽  
Integrated Electronics ◽  
Lattice Matching ◽  
Deposition Techniques

In the framework of a research aimed to superconductor/semiconductor integrated electronics, we have grown a-axis oriented YBa 2 Cu 3 O 7-δ (YBCO) thin films on silicon (100) substrates with (111) oriented insulating buffer layers of cerium dioxide ( CeO 2), using magnetron sputtering deposition techniques. The properties of the cerium dioxide layer have been preliminary optimized by means of several layout and by monitoring the growing procedures through X-ray diffraction, AFM and TEM techniques. The lattice matching between CeO 2 and YBCO resulted to be worsened by an amorphous thin SiO 2 layer at the Si/CeO 2 interface, that decouples the buffer orientation from the seed orientation. However, it was possible to grow a relatively thick, optimally textured layer of CeO 2 without spurious orientations. The YBCO films deposited on top of this layer result preferentially a-axis oriented. The transition widths are very large, jet well controllable and reproducible. Some technological applications can be already envisaged.

EPITAXIALLY GROWN YBCO THIN FILMS ON LOW LOSS LaAlO3 SUBSTRATE

1990 ◽  
Vol 04 (05) ◽  
pp. 369-373 ◽  
Author(s):  
Y. Z. ZHANG ◽  
L. LI ◽  
Y. Y. ZHAO ◽  
B. R. ZHAO ◽  
Y. G. WANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Low Loss ◽  
X Ray ◽  
Ybco Thin Films ◽  
Zero Resistance ◽  
Scanning Electron

A planar dc magnetron sputtering device was used to prepare high T c and high J c YBCO thin films. Both single crystal and polycrystal thin films were successfully grown on (100) oriented LaAlO 3 substrates. Zero resistance temperature T c0 = 92.3 K and critical current density J c (0) = 3.82 × 106 A/cm 2 at 77 K was obtained. The films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Formation and Characteristics of Thin Films of ZrO2-8 mol % Y2O3 Solid Electrolytes

2004 ◽  
Vol 97-98 ◽  
pp. 153-158 ◽  
Author(s):  
Darius Milčius ◽  
L.L. Pranevičius ◽  
V. Širvinskaitė ◽  
T. Šalkus ◽  
A. Kežionis ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid Electrolytes ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Cubic Symmetry ◽  
X Ray ◽  
Pulsed Dc ◽  
Pulsed Dc Magnetron Sputtering ◽  
Diffraction Patterns

Thin films of ZrO2-8mol%Y2O3 have been deposed by pulsed DC magnetron sputtering method. The substrates of Ni-cermet and alloy-600 for the films were used. The results of the investigation of the X-ray diffraction patterns and SEM showed that the films are nanocrystalline and belong to cubic symmetry. The relaxation process is related to the ion transport in thin films. The results of the investigation of the temperature dependencies of thin films ionic conductivity (σ) showed that the dependence σ(T) is caused by the temperature dependence of oxygen vacancy mobility, while the number of charge carriers remains constant with temperature.

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.

High-Jc YBCO Conductors Fabricated By Magnetron Deposition

2000 ◽  
Vol 616 ◽  
Author(s):  
N. Savvides ◽  
S. Gnanarajan ◽  
J. Herrmann ◽  
A. Thorley ◽  
A. Katsaros ◽  
...  
Keyword(s):  
Ion Beam ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Similar Degree ◽  
Magnetron Deposition ◽  
X Ray ◽  
Ion Beam Assisted Deposition ◽  
Pole Figures ◽  
Ybco Tapes ◽  
Biaxial Alignment

AbstractSuperconducting YBCO/YSZ/Hastelloy tapes or coated conductors were fabricated by combining ion beam assisted deposition (ILBAD) and magnetron sputtering techniques. The degree of biaxial alignment of the YSZ buffer layers and the epitaxial YBCO films was determined from x-ray pole figures and ø-scans. The best YSZ buffer layers had FWHFM δø= 7°- 10°. The corresponding YBCO tapes achieved a similar degree of biaxial alignment and high critical current density, Jc(77K,0T) = (0.9 – l.25)×106 A cm−2.

Reduced YSZ deposition temperatures for YBa2Cu3Ox/YSZ thin films on sapphire

1995 ◽  
Vol 10 (5) ◽  
pp. 1086-1090 ◽  
Author(s):  
J.H. Kroese ◽  
A.J. Drehrman ◽  
J.A. Horrigan
Keyword(s):  
Thin Films ◽  
Partial Pressure ◽  
Film Surface ◽  
Buffer Layers ◽  
Negative Ion ◽  
Partial Pressure Of Oxygen ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
Ybco Films ◽  
X Ray

Thin films of Y-stabilized ZrO2 (YSZ) were deposited by RF diode sputtering on R-plane sapphire as a buffer layer for the deposition of YBa2Cu3O3 (YBCO). By increasing the partial pressure of oxygen in the sputter gas mixture from 20% to 50%, it was found that the substrate temperature required to obtain (100) oriented YSZ deposition could be lowered to 630 °C from 800 °C. This change is attributed to heating or mixing effects at the film surface, due to an increase in negative ion bombardment, which supplements the effects of external heating. Increases in the partial pressure of oxygen beyond 50% were found to be counterproductive. YBCO films, deposited on the YSZ buffer layers via magnetron sputtering, showed c-axis orientation and transition temperatures of 82 K. Orientation of both the YSZ and YBCO films was confirmed by x-ray diffraction and SEM characterization.

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