Effects of Co-doping level on the microstructural and ferromagnetic properties of liquid-delivery metalorganic-chemical-vapor-deposited Ti1−xCoxO2 thin films

2002 ◽  
Vol 81 (22) ◽  
pp. 4209-4211 ◽  
Author(s):  
Nak-Jin Seong ◽  
Soon-Gil Yoon ◽  
Chae-Ryong Cho
Keyword(s):  
Thin Films ◽  
Doping Level ◽  
Chemical Vapor ◽  
Ferromagnetic Properties ◽  
Co Doping ◽  
Chemical Vapor Deposited ◽  
Metalorganic Chemical ◽  
Liquid Delivery

High-resolution electron microscopy investigations of stacking faults in Y1Ba2Cu3O7−δ metalorganic chemical vapor deposited thin films

1999 ◽  
Vol 14 (7) ◽  
pp. 2732-2738 ◽  
Author(s):  
Ch. Grigis ◽  
S. Schamm ◽  
D. Dorignac
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
High Resolution ◽  
Image Matching ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Chemical Vapor Deposited ◽  
Structural Imperfections ◽  
Metalorganic Chemical

New structural planar defects in Ba-deficient Y1Ba2Cu3O7−δ (YBCO) (1:1.6:3) thin films grown on NdGaO3 and SrTiO3 substrates by metalorganic chemical vapor deposition have been observed by means of high-resolution electron microscopy. The defects are associated with perturbations of the YBCO “1:2:3” stacking sequences along the c direction, which give rise to structural variants with locally “2:5:7,” “3:4:7,” or “4:6:10” cationic stoichiometries. The defects can be consistently interpreted as CuO–YO–CuO/CuO conversions or YO/BaO (BaO/YO) interconversions in the (a,b) planes and extending over a few nanometers along the c axis. Structural models based on image matching with simulations are proposed for two particular cases. It is thought that these structural imperfections can be effective sites of flux pinning.

Microstructures of La1−xAx(A = Ca or Sr)MnO3−δ thin films by liquid-delivery metalorganic chemical vapor deposition

2001 ◽  
Vol 16 (11) ◽  
pp. 3073-3083 ◽  
Author(s):  
Y. Xin ◽  
K. Han ◽  
N. Mateeva ◽  
H. Garmestani ◽  
P. N. Kalu ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Substrate Interface ◽  
Columnar Grains ◽  
Film Substrate ◽  
Metalorganic Chemical ◽  
Liquid Delivery

The microstructure of La1–xAx(A = Ca or Sr)MnO3–δ thin films grown by liquid-delivery metalorganic chemical vapor deposition on (001) MgO and (110)pseudo-cubic LaAlO3 were studied by transmission electron microscopy. The La1–xCaxMnO3–δ thin film on large lattice mismatched MgO exhibited very defective microstructures and consisted of two typical regions. The first region was close to the film–substrate interface and had an epitaxial relationship to the substrate with many differently oriented domains nucleated on the substrate surface. The second region consisted of columnar grains with some degree of texture. In contrast, the smaller lattice-mismatched La1–xSrxMnO3–δ/(110)pseudo-cubic LaAlO3 film had good crystalline quality with highly oriented columnar grains but exhibited complicated dislocation structures. Apart from the misfit dislocations formed at the film–substrate interface, two types of anomalous dislocations with limited contribution to relieving misfit stresses were also observed. One type of dislocation had extra planes in the film and some climbed into the substrate. These dislocations were considered to form from dislocation loops during nucleation of the film. The other type of dislocations had extra planes parallel to the film–substrate interface and glided into the substrate side resulting in a 2° tilt of the film with respect to the substrate. The complicated dislocation configurations present in the sample were related to the complex strain field in the film. The relative strains along the interface measured in the film were heterogeneous. The variations of the strains in the film were related to the local Curie temperature changes and second-order phase transitions of the film.

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