Growth of Tl-2212 Films on CeO2-Buffered Sapphire Substrates

2011 ◽  
Vol 197-198 ◽  
pp. 466-470
Author(s):  
Qing Lian Xie ◽  
Hong Wei Yue ◽  
Zi Qian Huang ◽  
Guo Hua Huang ◽  
Lu Ji ◽  
...  
Keyword(s):  
Deposition Temperature ◽  
Smooth Surface ◽  
Buffer Layers ◽  
Dc Magnetron Sputtering ◽  
Axis Orientation ◽  
Sapphire Substrates ◽  
Post Annealing ◽  
Two Temperature ◽  
Annealing Method

Tl2Ba2CaCu2O8(Tl-2212) films were prepared on r-cut sapphire substrates buffered with CeO2by dc magnetron sputtering and post-annealing method. Thein situtwo-temperature process was used to grow CeO2buffer layers. XRD and AFM measurements showed that CeO2films deposited at temperature of 370-470°C were excellent c-axis orientation and had smooth surface. SEM observations demonstrated that the Tl-2212 films’ surface morphology was changed from condensing crystal structure to plate-like structure when the CeO2deposition temperature was increased. The best Tl-2212 film’s critical temperature Tccan reach to 108.3 K, and critical current density Jcobtained at 5.33 MA/cm2(77 K, 0 T).

Growth of Double-Side Tl-2212 Thin Film on CeO2-Buffered MgO Substrate

2011 ◽  
Vol 194-196 ◽  
pp. 2384-2387 ◽  
Author(s):  
Qing Lian Xie ◽  
Yu Ting Zhang ◽  
Feng Cai Fang ◽  
Guo Hua Huang ◽  
Lu Ji ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Rf Magnetron Sputtering ◽  
Superconducting Films ◽  
Buffer Layers ◽  
Dc Magnetron Sputtering ◽  
Axis Orientation ◽  
Post Annealing ◽  
Current Densities ◽  
Mgo Substrate ◽  
Annealing Method

The double-side Tl-2212 films were fabricated on CeO2-buffered MgO substrates by dc magnetron sputtering and post-annealing method. The RF magnetron sputtering technology was used to grow CeO2buffer layers. XRD and SEM measurements showed that the CeO2films on annealed MgO substrates were highly c-axis orientation, and the Tl-2212 superconducting films on both sides had similar morphology and crystalline structure. For both sides of Tl-2212 films, the critical transition temperatures (Tc) were above 106 K, and the critical current densities (Jc) were above 2.2 MA/cm2(77 K, 0 T).

Growth of (0001) ZnO Thin Films on Sapphire

1996 ◽  
Vol 449 ◽  
Author(s):  
A. J. Drehman ◽  
P. W. Yip
Keyword(s):  
Surface Roughness ◽  
Buffer Layers ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force

ABSTRACTUsing reactive rf sputtering, we have grown (0001) oriented ZnO films in situ on heated c-axis sapphire substrates, that are promising, particularly in terms of surface roughness, as buffer layers for the subsequent epitaxial growth of III-V nitride films. We compare the effects of on-axis and off-axis sputter geometries on the film epitaxy and smoothness. We also examined the effect of substrate temperature on the growth and smoothness and quality of the film. X-ray diffraction was used to verify the hexagonal ZnO phase, its c-axis orientation and, qualitatively, the degree of its epitaxy. Atomic Force Microscopy (AFM) was used to determine the ZnO growth morphology and roughness. Our best films, obtained by off-axis sputter deposition, have a surface roughness of less than 1 nm.

Effect of CeO2 Deposition Temperature on the Properties of Tl-2212 Superconducting Films Grown on MgO Substrates

2011 ◽  
Vol 287-290 ◽  
pp. 188-192
Author(s):  
Qing Lian Xie ◽  
Guo Hua Huang ◽  
Yin Song Pan ◽  
Lu Ji ◽  
Hong Wei Yue ◽  
...  
Keyword(s):  
Deposition Temperature ◽  
Smooth Surface ◽  
Surface Resistance ◽  
Superconducting Films ◽  
Buffer Layers ◽  
Critical Transition ◽  
Surface Layers ◽  
Critical Transition Temperature ◽  
Axis Orientation

The preparation and superconductivity of Tl-2212 films grown on CeO2-buffered MgO substrates were investigated. AFM showed that the annealing of MgO substrates remarkably improved their crystal quality of surface layers, and led to the surface morphology of substrates evolving into unattached outgrowth structure with ultra-smooth surface. XRD measurements showed that CeO2buffer layers grown on MgO annealed at the suitable conditions were pure (00l) phase. The 500 nm thick Tl-2212 films grown on these CeO2films subsequently possessed excellent c-axis orientation and superconductivity. The best Tl-2212 film reached a low surface resistance of about 324 μΩ (10 GHz, 77 K), a critical current density as high as 3.5 MA/cm2(77 K, 0 T) and a critical transition temperature of about 108.4 K.

In-Situ Fluorescence Strain Sensing of the Stress in Interconnects

1994 ◽  
Vol 356 ◽  
Author(s):  
Q. Wen ◽  
Q. Ma ◽  
D. R. Clarke
Keyword(s):  
Laser Beam ◽  
Frequency Shift ◽  
Sapphire Substrate ◽  
Deposition Temperature ◽  
Spectroscopic Properties ◽  
Optical Microscope ◽  
Strain Sensing ◽  
Sapphire Substrates ◽  
Optical Fluorescence

AbstractAn optical fluorescence method is introduced for determining the localized stresses in passivated aluminum lines on sapphire substrates containing a thin epitaxial ruby film at the AI/AI2O3 interface. The method is based on the piezo-spectroscopic properties of the ruby film, which acts as an in situ sensor. By focusing a laser beam through the sapphire substrate and onto the bottom of an aluminum line, the fluorescence from the ruby sensor can be excited and collected through an optical microscope. The frequency shift of the fluorescence lines is proportional to the stress in the aluminum line. To illustrate our observations two sets of measurements are presented: the spatial variation perpendicular to an interconnect line; and the temperature dependence on heating upto the deposition temperature of the SiN used to passivate the interconnects.

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°.

scholarly journals The in situ two-temperature process of preparation of CeO2 films on sapphire substrates and technical improvements of fabrication of Tl-2212 films

2009 ◽  
Vol 58 (11) ◽  
pp. 7958
Author(s):  
Xie Qing-Lian ◽  
Wang Zheng ◽  
Huang Guo-Hua ◽  
Wang Xiang-Hong ◽  
You Feng ◽  
...  
Keyword(s):  
Sapphire Substrates ◽  
Ceo2 Films ◽  
Two Temperature

Epitaxy of Molybdenum on Sapphire

1973 ◽  
Vol 31 ◽  
pp. 40-41
Author(s):  
J. E. O'Neal ◽  
B. B. Rath
Keyword(s):  
Deposition Temperature ◽  
Electron Beam Evaporation ◽  
Sapphire Substrates ◽  
Thermal Etching ◽  
Substrate Surfaces ◽  
Single Crystal Sapphire ◽  
Structure Orientation ◽  
Deposited Films ◽  
Reflection Electron Diffraction

Thin films of molybdenum were deposited by the electron beam evaporation method on single crystal sapphire substrates to establish the effects of substrate orientation, deposition temperature, and evaporation rate on the structure, orientation and morphology of the deposited films. The films were characterized by replication and high resolution reflection electron diffraction methods.The epitaxy of molybdenum on sapphire substrates of orientations (0001), (1012), and (1012) were studied over a substrate temperature range of 25 through 1000°C with deposition rates of 500 and 1000 Å/min. Strain-free substrate surfaces were prepared by removing the disturbed surface layer by means of thermal etching in-situ at 1450°C for 2 hours in a pressure of 10−9 Torr.

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