HREM of Epitaxial YBa2Cu3O7 Thin Films

1990 ◽  
Vol 183 ◽  
Author(s):  
T. E. Mitchell ◽  
S. N. Basu ◽  
M. Nastasi ◽  
T. Roy
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Grain Boundaries ◽  
Critical Current ◽  
Current Density ◽  
Small Angle ◽  
Stacking Faults ◽  
Cross Sectional ◽  
Relationship Of ◽  
The Relationship

AbstractThin films of YBa2Cu3O7 have been prepared by evaporation of Cu, Y and BaF2 onto (001) SrTiO3, LaGaO3. and LaAlO3 and subsequent annealing. Their microstructures have been examined by HREM of cross-sectional specimens. Epitaxial (001) grains of YBa2Cu3O7 form near the substrate interface in thin films but (001) and (010) grains tend to nucleate as the film thickens. 90° grain boundaries are therefore common, as well as other defects such as small-angle boundaries, dislocations and stacking faults. HREM of the substrate/superconductor interface indicates regions of perfect epitaxy, highly distorted areas, amorphous regions and areas showing evidence of interdiffusion. The relationship of these microstructural features to critical current density is discussed.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Effects of surface damage on critical current density in MgB2 thin films

2021 ◽  
Vol 22 ◽  
pp. 14-19
Author(s):  
Soon-Gil Jung ◽  
Duong Pham ◽  
Jung Min Lee ◽  
Yoonseok Han ◽  
Won Nam Kang ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Surface Damage ◽  
Mgb2 Thin Films

Characterization of Epitaxial Superconducting YBacuO Thin Films with Three Different Orientations

1989 ◽  
Vol 169 ◽  
Author(s):  
X.K. Wang ◽  
D.X. Li ◽  
S.N. Song ◽  
J.Q. Zheng ◽  
R.P.H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Orientation Dependence ◽  
Zero Field ◽  
Epitaxial Thin Films ◽  
Oriented Film ◽  
Zero Resistance ◽  
Xrd Patterns

AbstractEpitaxial thin films of YBaCuO were prepared by multilayer deposition from Y, Cu, and BaF2 sources with: (1) the a‐axis perpendicular to (100)SrTiO3; (2) the c‐axis perpendicular to (100)SrTiO3; and (3) the [110] axis perpendicular to (110)SrTiO3. XRD patterns as well as SEM and HREM images confirm that the films are highly oriented, essentially epitaxial. Both the a‐axis oriented and the c‐axis oriented films exhibit zero resistance at 91K. The [110] oriented film shows the sharpest transiton with a transition width of IK and zero resistance at 85K. The zero field critical current density, Jc, determined magnetically, is in excess of 107A/cm2 at 4.4K and 1.04 x 106A/cm2 at 77K for the c‐axis oriented film; for the a‐axis oriented film we obtained 6.7 x 106A/cm2 at 4.4K and 1.2 x 105A/cm2 at 77K. The orientation dependence of the critical current density in the basal plane of the a‐axis oriented film was studied. The largest Jc's occur along the in‐plane <100> axes of the substrate.

Critical current density and flux pinning in Gd1−xYxBa2Cu3O7−y epitaxial thin films

1995 ◽  
Vol 250 (1-2) ◽  
pp. 55-58 ◽  
Author(s):  
R.L. Wang ◽  
H.C. Li ◽  
B. Yin ◽  
J.W. Li ◽  
X.S. Ron ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Epitaxial Thin Films

Rapid and simple measurement of critical current density in HTS thin films using a permanent magnet method

2005 ◽  
Vol 426-431 ◽  
pp. 1122-1126 ◽  
Author(s):  
A. Saito ◽  
K. Takeishi ◽  
Y. Takano ◽  
T. Nakamura ◽  
M. Yokoo ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Permanent Magnet ◽  
Critical Current ◽  
Current Density ◽  
Simple Measurement
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