(001) Bi2Sr2Ca2Cu3O10Superconducting Thin Films on Substrates with Large Film−Substrate Lattice Mismatch and Different Film−Substrate Lattice Mismatch Anisotropy

2009 ◽  
Vol 9 (1) ◽  
pp. 391-394 ◽  
Author(s):  
K. Endo ◽  
P. Badica
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Film Substrate

Microstructure of SrTiO3 Thin Films as Single Layer and Incorporated in Yba2Cu3O7-x/SrTiO3 Multilayers

1995 ◽  
Vol 401 ◽  
Author(s):  
L. Ryen ◽  
E. Olssoni ◽  
L. D. Madsen ◽  
C. N. L. Johnson ◽  
X. Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Lattice Mismatch ◽  
Single Layer ◽  
Transmission Electron ◽  
Tilt Boundaries ◽  
Interfacial Dislocations ◽  
The Individual ◽  
Film Substrate

AbstractEpitaxial single layer (001) SrTiO3 films and an epitaxial Yba2Cu3O7-x/SrTiO3 multilayer were dc and rf sputtered on (110)rhombohedral LaAIO3 substrates. The microstructure of the films was characterised using transmission electron microscopy. The single layer SrTiO3 films exhibited different columnar morphologies. The column boundaries were due to the lattice mismatch between film and substrate. The boundaries were associated with interfacial dislocations at the film/substrate interface, where the dislocations relaxed the strain in the a, b plane. The columns consisted of individual subgrains. These subgrains were misoriented with respect to each other, with different in-plane orientations and different tilts of the (001) planes. The subgrain boundaries were antiphase or tilt boundaries.The individual layers of the Yba2Cu3O7-x/SrTiO3 multilayer were relatively uniform. A distortion of the SrTiO3 unit cell of 0.9% in the ‘001’ direction and a Sr/Ti ratio of 0.62±0.04 was observed, both in correspondence with the single layer SrTiO3 films. Areas with different tilt of the (001)-planes were also present, within each individual SrTiO3 layer.

Microstructure of laser-ablated superconducting La2CuO4Fx thin films on SrTiO3

2001 ◽  
Vol 16 (11) ◽  
pp. 3309-3316 ◽  
Author(s):  
G. Kong ◽  
M. O. Jones ◽  
J. S. Abell ◽  
P. P. Edwards ◽  
S. T. Lees ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Microstructural Analysis ◽  
Stacking Faults ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Elemental Fluorine ◽  
Deposit Surface ◽  
Film Substrate ◽  
Post Deposition

Thin films of lanthanum cuprate were grown on SrTiO3 substrates by pulsed laser deposition and made superconducting (Tc ∼ 38 K) through the process of post-deposition fluorination using elemental fluorine. A microstructural analysis showed that the [110] zone of the film grows parallel to the [100] zone of the SrTiO3 substrate, reducing the lattice mismatch from 37.5% to 2.4%. At the film–substrate interface there is an intermediate layer 3–4 nm thick and twin-related grains emanate from this region. Stacking faults are present in the bulk of the film, with misoriented subgrains present at the deposit surface.

Variant structure in metal-organic-chemical-vapor-deposition-derived SnO2 thin films on sapphire (0001)

1995 ◽  
Vol 10 (6) ◽  
pp. 1516-1522 ◽  
Author(s):  
Donhang Liu ◽  
Q. Wang ◽  
H.L.M. Chang ◽  
Haydn Chen
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Film Substrate ◽  
Organic Chemical Vapor Deposition

Tin oxide (SnO2) thin films were deposited on sapphire (0001) substrate by metal-organic chemical vapor deposition (MOCVD) at temperatures of 600 and 700 °C. The microstructure of the deposited films was characterized by x-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). At the growth conditions studied, films were single-phase rutile and epitaxial, but showed variant structures. Three distinct in-plane epitaxial relationships were observed between the films and the substrate. A crystallographic model is proposed to explain the film morphology. This model can successfully predict the ratio of the width to the length of an averaged grain size based upon the lattice mismatch of the film-substrate interface.

Pulsed Laser Deposition of BaxSr1-xTiO3 Thin Films for Frequency Agile Microwave Electronics

1998 ◽  
Vol 526 ◽  
Author(s):  
W. Chang ◽  
J. S. Horwitz ◽  
J. M. Pond ◽  
S. W. Kirchoefer ◽  
D B. Chrisey
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Dielectric Behavior ◽  
Laser Deposition ◽  
Film Stress ◽  
Bst Films ◽  
The Difference ◽  
Film Substrate

AbstractOriented, single phase thin films (~5000Å thick) of BaxSr1-xTiO3 (BST) have been deposited on to (100) MgO and LaAlO3 (LAO) single crystal substrates using pulsed laser deposition (PLD). A strong correlation is observed between the microstructure of the deposited film and the dielectric tuning and loss at microwave frequencies. Microstructural defects observed in as deposited films include strain, due to film substrate lattice mismatch and oxygen and cation vacancies. Compensation of the ablation target with excess Ba and Sr is observed to increase the dielectric constant and to reduce the dielectric loss. Post-deposition, bomb annealing of films at high temperatures (1250°C) is observed to fill oxygen vacancies and increase grain size. The difference in the dielectric behavior for as-deposited and low temperature annealed BST films on MgO and BST films on LAO is observed and may be attributed to the differences in film stress. A further improvement in the dielectric behavior is observed by the addition of donor/acceptor dopants such as Mn. The data shows that ferroelectric thin films can be used to build tunable microwave circuits that offer significant performance advantages over devices made from conventional semiconducting materials.

Single-crystal and Nano-columnar Growth of Gadolinium-doped Ceria Thin Films on Oxide Substrates Studied Using Electron Microscopy

2003 ◽  
Vol 795 ◽  
Author(s):  
D. X. Huang ◽  
C. L. Chen ◽  
A. J. Jacobson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Single Crystal ◽  
Grain Growth ◽  
Lattice Mismatch ◽  
Compressive Strain ◽  
Doped Ceria ◽  
Columnar Grain ◽  
Film Substrate ◽  
Gadolinium Doped Ceria

ABSTRACTGadolinium-doped ceria (GDC) thin films were grown by pulsed laser ablation on various oxide single crystal substrates including MgO, YSZ, LAO, NGO, and STO with different film-substrate lattice mismatch ratios. The film microstructures were characterized mainly by using electron microscopy. A clear influence of the filmsubstrate lattice mismatch on the film crystallinity has been observed. The GDC films usually exhibit columnar grain growth for a large range of film-substrate lattice mismatch ratios. A cube-on-cube growth of GDC film on MgO has been observed with a surprisingly high lattice mismatch ratio of 28%. The highest film crystallinity is obtained on the LAO substrates under a small compressive strain. This single-crystalline GDC film shows no columnar grain growth but presents a novel directionally-aligned precipitated Gd-rich nanoparticle system, which plays a specific role in relaxing various kinds of strain fields induced during the thin film growth to ensure the film crystallinity.

Scanning Tunneung Microscope Studies of Initial Epitaxial Growth of YBa2Cu3O7-δ Thin Films

1992 ◽  
Vol 263 ◽  
Author(s):  
Xiang-Yang Zheng ◽  
D. H. Lowndes ◽  
Shen Zhu ◽  
R. J. Warmack
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Lattice Mismatch ◽  
Growth Mode ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Weber Type ◽  
Film Substrate ◽  
Miscut Angle

ABSTRACTThe initial stages of epitaxial growth of laser ablated YBa2Cu3O7-δ (YBCO) thin films on (001) SrTiO3, LaAlO3, and MgO substrates, and on slightly miscut LaA1O3 and SrTiO3, have been studied with scanning tunneling microscopy (STM). Surface images show that the initial YBCO growth mode can be either of the Stranski- Krastanov or the Volmer-Weber type, depending on the film-substrate lattice mismatch and the growth temperature. A small substrate miscut angle is found to strongly influence the growth mode of YBCO films. Screw dislocation-mediated growth is suppressed, and films grown at 800°C on (001) LaAlO3 substrates with miscut angle of 2.0° along <100> or <110> directions were found to consist of tilted platelets that are epitaxially aligned with the substrate crystal lattice.

TEM study of a laser ablated YBa2Cu3O7−x thin film on MgO substrate

1990 ◽  
Vol 48 (4) ◽  
pp. 28-29
Author(s):  
C. Traeholt
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Cross Sectional ◽  
X Ray ◽  
Major Interest ◽  
The Common ◽  
Film Substrate ◽  
Oriented Parallel ◽  
Rotating Target ◽  
Mgo Substrate

Since the high Tc superconductors were discovered, the most common compounds have been investigated in detail. This work has mainly been done on bulk specimens. Now as the preparation of these high Tc superconductors is well controlled with respect to the common compounds, thin films become of major interest. In order to study the film—substrate interface cross-sectional specimens for TEM have here been prepared and investigated considering the process of image formation.Thin films, about 100 nm thick, were laser ablated onto a single crystal MgO substrate. This was done in an oxygen atmosphere and with a rotating target of stoichiometric YBa2Cu3O7−x. The subsequent X—ray analysis showed what was believed to be an epitaxially grown film, with its c—axis only deviating a few degrees from the substrate normal. The a— and b—axes of the film were oriented parallel to the <100> directions of the substrate, in spite of a lattice mismatch (YBa2Cu3O7−x a = 3.82 Å, b = 3.89 Å, c = 11.68 Å; MgO a = b = c = 4.2 Å).

Effect of lattice mismatch on the epitaxy of sol-gel LiNbO3 thin films

1997 ◽  
Vol 12 (5) ◽  
pp. 1391-1400 ◽  
Author(s):  
T. A. Derouin ◽  
C. D. E. Lakeman ◽  
X. H. Wu ◽  
J. S. Speck ◽  
F. F. Lange
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Lattice Mismatch ◽  
Sol Gel ◽  
Mismatch Strain ◽  
Transmission Electron ◽  
Solution Precursor ◽  
Growth Method ◽  
Film Substrate ◽  
Interfacial Plane

A solution precursor method based on metal alkoxides was used to produce epitaxial LiNbO3 thin films, ≈200 nm thick, on (0001) sapphire substrates. Transmission electron. microscopy revealed that the major cause of surface roughness in these films was grain boundary grooves between mosaic grains with misorientations ≤5°. It is postulated that these low angle boundaries directly result in surface grooving and roughness. The epitaxial films also contained two distinguishable variants in the film/substrate interfacial plane, namely, an aligned variant, and a 60° rotated variant, . A seeded grain growth method was used to minimize the presence of the 60° rotated variant. An epitaxial buffer layer of Fe2O3 was used to lower the mismatch strain, eliminate the 60° rotated variant, and reduce the mosaic nature of the LiNbO3 film. X-ray rocking curve full-width-at-half-maximum (FWHM) values measured on the film peak indicate that the mosaic character can be reduced from 1.5° to 0.76° by using a buffer layer.

Electron Channeling Analysis of Elastic Strains in InGaAs Thin Films

1989 ◽  
Vol 160 ◽  
Author(s):  
R. Keller ◽  
W. Zielinski ◽  
W.W. Gerberich ◽  
J.A. Kozubowski
Keyword(s):  
Thin Films ◽  
Elastic Strain ◽  
Lattice Mismatch ◽  
Electron Channeling ◽  
Gaas Substrates ◽  
Strain Determination ◽  
Film Substrate ◽  
Line Positions ◽  
Elastic Strain Field ◽  
Elastic Strains

AbstractInx Ga1-x As thin films were grown by MBE on (001) GaAs substrates. The associated 1% lattice mismatch resulted in the development of an elastic strain field in the systems. Electron channeling patterns (ECP) were then obtained from these samples in an SEM at different accelerating voltages, allowing data to be obtained over various information depths within the samples while keeping them intact. The ECPs showed sensitivity to the elastic strains both parallel and perpendicular to the film/substrate interface. Certain high order Laue zone (HOLZ) line positions showed good sensitivity to the Poisson strain in the films due to a rotation of atomic planes. These line positions varied with film thickness and distance from the interface. The technique shows promise as a tool for relatively easy elastic strain determination. Its limitations will also be discussed.

Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

1991 ◽  
Vol 49 ◽  
pp. 562-563
Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thin Films ◽  
Diffraction Pattern ◽  
Annealing Temperature ◽  
Lattice Mismatch ◽  
Si Substrate ◽  
Metal Thin Films ◽  
Transmission Electron ◽  
Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

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