Transmission electron microscopy studies of a CeO2/Gd2Zr2O7 buffer layer on an Ni-based alloy for YBCO coated conductor

2004 ◽  
Vol 412-414 ◽  
pp. 813-818 ◽  
Author(s):  
T. Kato ◽  
T. Muroga ◽  
Y. Iijima ◽  
T. Saitoh ◽  
T. Hirayama ◽  
...  
1990 ◽  
Vol 216 ◽  
Author(s):  
S.G. Lawson-Jack ◽  
I.P. Jones ◽  
D.J. Williams ◽  
M.G. Astles

ABSTRACTTransmission electron microscopy has been used to assess the defect contents of the various layers and interfaces in (CdHg) Te heterostructures. Examination of cross sectional specimens of these materials suggests that the density of misfit dislocations at the interfaces is related to the layer thicknesses, and that the high density of dislocations which are generated at the GaAs/CdTe interface are effectively prevented from penetrating into the CdHgTe epilayer by a 3um thick buffer layer. The majority of the dislocations in the layers were found to have a Burgers vector b = a/2<110> and either lie approximately parallel or inclined at an angle of ∼ 60° to the interfacial plane.


2007 ◽  
Vol 21 (18n19) ◽  
pp. 3348-3351
Author(s):  
J. YANG ◽  
H. Z. LIU ◽  
H. ZHANG ◽  
F. QU ◽  
Q. ZHOU ◽  
...  

A composite buffer of CeO 2/ YSZ / Y 2 O 3 was investigated on the biaxially textured NiW long tape for YBCO coated conductor with magnetron sputtering technique. Every layer's surface morphology was observed by scanning electron microscopy. The seed layer Y 2 O 3 film was full coverage of the NiW substrate. The cap layer CeO 2 showed a smooth and crack-free surface and good crystallinity. The roughness of CeO 2 surface was measured by atom force microscopy. The transmission electron microscopy was used to analyze the cross-section of buffer layers and YBCO layer.


2012 ◽  
Vol 725 ◽  
pp. 75-78
Author(s):  
Noriko Ohmori ◽  
Tomonori Uchimaru ◽  
Hiroyuki Fujimori ◽  
Jun Komiyama ◽  
Yoshihisa Abe ◽  
...  

The dislocations in GaN thin film with GaN/AlN multilayer (ML) as the buffer layer were evaluated using transmission electron microscopy. A high density of dislocations parallel to the GaN/ML interface and a sudden decrease in the dislocation density at the GaN/ML interface were found. Dislocation propagation in the direction parallel to the GaN/ML interface by turning horizontally on the GaN/ML interface is considered to be effective in decreasing the dislocation density at the top layer of GaN.


2000 ◽  
Vol 15 (2) ◽  
pp. 476-482 ◽  
Author(s):  
Hirotoshi Nagata ◽  
Yasuyuki Miyama ◽  
Naoki Mitsugi ◽  
Kaori Shima

The fabrication process of an Al thin-film optical polarizer on LiNbO3 waveguides after CF4 plasma dry etching of a previously deposited SiO2 buffer layer was investigated. The problem in this process is a precipitation of compounds containing C, O, F, and Li on the etched LiNbO3 surface and a chemical deterioration of the Al caused by a reaction with these precipitates. Most notably, the growth of amorphous phase in addition to the crystalline Al metal grains and a partial oxidization of Al were found at the interface using transmission electron microscopy and x-ray photoelectron spectroscopy.


1990 ◽  
Vol 198 ◽  
Author(s):  
Eiichi Murakami ◽  
Hiroyuki Etoh ◽  
Akio Nishida ◽  
Kiyokazu Nakagawa ◽  
Masanobu Miyao

ABSTRACTElectrical characteristics of modulation-doped p-Si0.5Ge0.5/Ge/Si1−x Gex heterostructures are examined in relation to Si fraction (1−X) and thickness (dB)of the buffer layer (Si1−xGex), using Raman spectroscopy and transmission electron microscopy. Strain-induced enhancement of hole mobility and concentration is observed in 1-X≦0.25. However, their decrease in 1-X≦0.25 and for small dB values is also observed, which is attributed to the increase in threading dislocations. As a result, a maximum hole mobility of 7600 cm2/Vs at 77 K is obtained at 1-X=0.25 and dB=1μm.


1987 ◽  
Vol 104 ◽  
Author(s):  
E. A. Fitzgerald ◽  
P. D. Kirchner ◽  
G. D. Petit ◽  
J. M. Woodall ◽  
D. G. Ast

ABSTRACTThe defect structure of lattice-mismatched one micron In0.12 Ga0.88As epilayers on (001) GaAs was studied with scanning cathodoluminescence (CL) and transmission electron microscopy (TEM). CL examination of the GaAs buffer layer revealed the formation of a segmented network of defects below the interface. Cross-sectional TEM analysis shows that these defects are dislocation half-loops extending from the interface, and the vast majority of these loops lie on the GaAs side of the interface. The dislocations in the GaAs buffer layer were determined to be edge dislocations. Thus, CL images show that edge dislocations in this system are centers for non-radiative recombination. We propose that two 60° dislocations with opposite screw and interface tilt components can glide into the buffer layer to form edge dislocations. Potential energy plots for 60° dislocations near the interface and interacting with interface dislocations supports this model.


1994 ◽  
Vol 28 (1-3) ◽  
pp. 497-501 ◽  
Author(s):  
D. González ◽  
D. Araújo ◽  
S.I. Molina ◽  
A. Sacedón ◽  
E. Calleja ◽  
...  

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