Deposition Rate Effect on Critical Thickness of BaTiO3 Epitaxial Thin Film Grown on SrTiO3 (001)

2007 ◽  
Vol 1034 ◽  
Author(s):  
Masanori Kawai ◽  
Daisuke Kan ◽  
Seiichi Isojima ◽  
Hiroki Kurata ◽  
Seiji Isoda ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Deposition Rate ◽  
Critical Thickness ◽  
High Deposition Rate ◽  
Misfit Dislocations ◽  
Epitaxial Thin Films ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractBaTiO3/SrTiO3(001) epitaxial thin films were prepared at various growth rates by pulsed laser deposition, and their heterostructures were evaluated by synchrotron x-ray diffraction measurements and cross-sectional scanning transmission electron microscopy observations. In a film grown at a low deposition rate (0.01 nm/s), misfit dislocations are found near the interface and a fully relaxed BaTiO3 thin film grows epitaxially on the substrate. On the other hand, a film grown at a high deposition rate (0.04 nm/s) consists of strained and relaxed BaTiO3 lattices. Our results showed that the critical thickness of BaTiO3/SrTiO3(001) epitaxial thin films can be controlled by the deposition rate and that the critical thickness increases with increasing the deposition rate, and by adjusting the deposition rate we were able to prepare epitaxial thin films consisting of fully strained BaTiO3, partially strained BaTiO3 or fully relaxed BaTiO3. We have also achieved the growth controlling of BaTiO3 thin films on SrTiO3(001) substrates with SrRuO3 bottom electrode layer.

Electron Microscopy Studies of The Chemistry And Microstructure of BaF2 / YBa2Cu3O7-x Thin Films

1994 ◽  
Vol 52 ◽  
pp. 796-797
Author(s):  
J. L. Lee ◽  
C. A. Weiss ◽  
R. A. Buhrman ◽  
J. Silcox
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Scale ◽  
Island Growth ◽  
Multilayer Systems ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Mgo Substrate

BaF2 thin films are being investigated as candidates for use in YBa2Cu3O7-x (YBCO) / BaF2 thin film multilayer systems, given the favorable dielectric properties of BaF2. In this study, the microstructural and chemical compatibility of BaF2 thin films with YBCO thin films is examined using transmission electron microscopy and microanalysis. The specimen was prepared by using laser ablation to first deposit an approximately 2500 Å thick (0 0 1) YBCO thin film onto a (0 0 1) MgO substrate. An approximately 7500 Å thick (0 0 1) BaF2 thin film was subsequendy thermally evaporated onto the YBCO film.Images from a VG HB501A UHV scanning transmission electron microscope (STEM) operating at 100 kV show that the thickness of the BaF2 film is rather uniform, with the BaF2/YBCO interface being quite flat. Relatively few intrinsic defects, such as hillocks and depressions, were evident in the BaF2 film. Moreover, the hillocks and depressions appear to be faceted along {111} planes, suggesting that the surface is smooth and well-ordered on an atomic scale and that an island growth mechanism is involved in the evolution of the BaF2 film.

Growth of a-plane ZnO Thin Films on r-plane Sapphire by Plasma-assisted MBE

2005 ◽  
Vol 891 ◽  
Author(s):  
Junqing Q. Xie ◽  
J. W. Dong ◽  
A. Osinsky ◽  
P. P. Chow ◽  
Y. W. Heo ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Defect Density ◽  
Zno Thin Films ◽  
Rf Plasma ◽  
Misfit Dislocations ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Small Lattice

ABSTRACTZnO thin films have been epitaxially grown on r-plane sapphire by RF-plasma-assisted molecular beam epitaxy. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies indicate that the epitaxial relationship between ZnO and r-plane sapphire is (1120)ZnO // (1102)sapphire and [0001]ZnO // [1101]sapphire. Atomic force microscopy measurements reveal islands extended along the sapphire [1101] direction. XRD omega rocking curves for the ZnO (1120) reflection measured either parallel or perpendicular to the island direction suggest the defect density anisotropy along these directions. Due to the small lattice mismatch along the ZnO [0001] direction, few misfit dislocations were observed at the ZnO/Al2O3 interface in the high-resolution cross-sectional TEM image with the zone axis along the ZnO [1100] direction.

scholarly journals Effects of Te- and Fe-doping on the superconducting properties in FeySe1-xTex thin films

2021 ◽  
Author(s):  
Yalin Zhang ◽  
Tong Wang ◽  
Zhihe Wang ◽  
Zhongwen Xing
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Interfacial Structure ◽  
Epitaxial Thin Films ◽  
Superconducting Transition ◽  
Transmission Electron ◽  
Fe Content ◽  
Scanning Transmission ◽  
Microscopy Images ◽  
Deposition Technology

Abstract High quality FeySe1−xTex epitaxial thin films have been fabricated on TiO2-buffered SrTiO3 substrates by pulsed laser deposition technology. There is a significant composition deviation between the nominal target and the thin film. Te doping can affect the Se/Te ratio and Fe content in chemical composition. The superconducting transition temperature Tc is closely related to the chemical composition. Fe vacancies are beneficial for the FeySe1−xTex films to exhibit the higher Tc. A 3D phase diagram is given that the optimize range is x = 0.13 − 0.15 and y = 0.73 − 0.78 for FeySe1−xTex films. The anisotropic, effective pining energy and critical current density for the Fe0.72Se0.94Te0.06, Fe0.76Se0.87Te0.13 and Fe0.91Se0.77Te0.23 samples were studied in detail. The scanning transmission electron microscopy images display a regular pattern without obviously scale defects at the interfacial structure.

Si1-xGex Critical Thickness for Surface Wave Generation During UHV-CVD Growth at 525°C

1995 ◽  
Vol 399 ◽  
Author(s):  
H. Lafontaine ◽  
D.C. Houghton ◽  
B. Bahierathan ◽  
D.D. Perovic ◽  
J.-M. Baribeau
Keyword(s):  
Electron Microscopy ◽  
Surface Waves ◽  
Critical Thickness ◽  
Critical Value ◽  
Misfit Dislocations ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Cvd Growth

ABSTRACTSeveral Si1-xGex/Si heterostructures were grown at 525°C using a commercially available UHV-CVD reactor. Layers with a germanium fraction ranging from 0.15 to 0.5 were examined by means of cross-sectional transmission electron microscopy and atomic force microscopy. Surface waves were found in layers with a thickness above a critical value which decreases rapidly as the Ge fraction is increased. Both experimental and modeling results show that surface waves are generated before misfit dislocations for Ge fractions above 0.3.

Epitaxial Thin Films And Heterostrcutures of Various Isotropic Metallic Oxides for Device Applications

1994 ◽  
Vol 341 ◽  
Author(s):  
C. B. Eom ◽  
Julia M. Phillips ◽  
R. J. Cava
Keyword(s):  
Thin Films ◽  
Cuprate Superconductors ◽  
Superconducting Devices ◽  
Epitaxial Thin Films ◽  
Metallic Oxide ◽  
Cross Sectional ◽  
Lattice Match ◽  
Metallic Oxides ◽  
Transmission Electron ◽  
Device Applications

AbstractWe have grown epitaxial thin films of various isotropic metallic oxides such as Sr1-xCaxRuO3 and La8-xSrxCu8O2Oin situ by 90° off-axis sputtering. These metallic oxides are pseudo-cubic perovskites with essentially isotropic properties, which could be ideal normal metals for SNS junctions in superconducting devices and for electrodes in ferroelectric devices. We have fabricated epitaxial ferroelectric heterostructures [SrRuO3/Pb(Zr0. 52 Ti0.4 8) O3 /SrRuO3] employing isotropic metallic oxide (SrRuO3) electrodes on substrates of (100) SrTiO3 and (100) Si with an yttria stabilized zirconia buffer layer. They exhibit superior fatigue characteristics over those made with metal electrodes, showing little degradation over 10 cycles, with a large remnant polarization (27 μC/cm2 ). We have also grown epitaxial superconducting heterostructures (YBa2Cu3O7 / La8-xSrxCu8O2O / YBa2Cu3O7 ) with a copper-oxide-based isotropic metallic oxide (La8-xSrxCu8O20) normal metal barrier. X-ray diffraction and cross-sectional transmission electron microscopy reveal these heterostructures to have high crystalline quality and clean interfaces. This material will facilitate fabrication of ideal SNS Josephson junctions with low boundary resistance due to its excellent chemical compatibility and lattice match with cuprate superconductors and will be useful for determining the source of interface resistance in such heterostructures.

Heteroepitaxial Bi2Sr2CaCu2Ox Superconducting thin films Deposited on LaA1O3 by Solid Phase Epitaxy and OMCVD

1992 ◽  
Vol 275 ◽  
Author(s):  
J. Chen ◽  
H. A. Lu ◽  
F. DiMeo ◽  
B. W. Wessels ◽  
D. L. Schulz ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Superconducting Thin Films ◽  
Epitaxial Thin Films ◽  
Solid Phase Epitaxy ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Film Substrate

ABSTRACT-Heteroepitaxial superconducting Bi,Sr2CaCu2Ox (BSCCO 2212) thin films have been formed by solid phase epitaxy from amorphous films deposited on (100) LaA1O3 single crystal substrates by organometallic chemical vapor deposition. The epitaxial structure of the film is confirmed by x-ray diffraction including θ/2θ and Φ (in plane rotation) scans. Cross-sectional high resolution transmission electron microscopy indicates that the film-substrate interface is nearly atomically abrupt. Improvements in superconducting properties of the epitaxial thin films are noted in comparison to highly textured films deposited on MgO.

scholarly journals Effects of Te- and Fe-doping on the superconducting properties in FeySe1−xTex thin films

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yalin Zhang ◽  
Tong Wang ◽  
Zhihe Wang ◽  
Zhongwen Xing
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Interfacial Structure ◽  
Epitaxial Thin Films ◽  
Superconducting Transition ◽  
Transmission Electron ◽  
Fe Content ◽  
Scanning Transmission ◽  
Microscopy Images ◽  
Deposition Technology

AbstractHigh quality FeySe1−xTex epitaxial thin films have been fabricated on TiO2-buffered SrTiO3 substrates by pulsed laser deposition technology. There is a significant composition deviation between the nominal target and the thin film. Te doping can affect the Se/Te ratio and Fe content in chemical composition. The superconducting transition temperature Tc is closely related to the chemical composition. Fe vacancies are beneficial for the FeySe1−xTex films to exhibit the higher Tc. A 3D phase diagram is given that the optimize range is x = 0.13–0.15 and y = 0.73–0.78 for FeySe1−xTex films. The anisotropic, effective pining energy, and critical current density for the Fe0.72Se0.94Te0.06, Fe0.76Se0.87Te0.13 and Fe0.91Se0.77Te0.23 films were studied in detail. The scanning transmission electron microscopy images display a regular atomic arrangement at the interfacial structure.

Structure and Morphology of Epitaxially Intergrown (100)- and (116)-Oriented SrBi2Ta2O9 Ferroelectric Thin Films on SrLaGaO4(110) Substrates

2001 ◽  
Vol 688 ◽  
Author(s):  
H. N. Lee ◽  
D. N. Zakharov ◽  
P. Reiche ◽  
R. Uecker ◽  
D. Hesse
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Scanning Force Microscopy ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Integrated Intensity ◽  
Scanning Force

AbstractSrBi2Ta2O9 (SBT) epitaxial thin films having a mix of (100) and (116) orientations have been grown on SrLaGaO4(110) by pulsed laser deposition. X-ray diffraction θ2 θ and pole figure scans, and cross-sectional transmission electron microscopy (TEM) analyses revealed the presence of two epitaxial orientations, SBT(100) ∥ SLG(110); SBT[001] ∥ SLG[001] and SBT(116) ∥ SLG(110); SBT [110] ∥ SLG[001]. By calculating the integrated intensity of certain x-ray diffraction peaks, it was established that the crystallinity and the in-plane orientation of the (100) and (116) orientation are best at a substrate temperature of 775 °C and 788 °C, respectively, and that the volume fraction of the (100) orientation at about 770 °C reached about 60%. By scanning force microscopy and cross-sectional TEM investigations we found that the a-axisoriented grains are rounded and protrude out due to the rapid growth along the [110] direction, leading to a distinct difference of the surface morphology between (100)- and (116)-oriented grains.

Interfacial Strain Reliefs in Epitaxial YBa2Cu3O7–δ Thin Films Grown on SrTiO3 Buffered MGO Substrates

1997 ◽  
Vol 505 ◽  
Author(s):  
Xingtian Cui ◽  
Q. Y Chen ◽  
Yongxiang Guo ◽  
W. K. Chu
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rutherford Backscattering Spectrometry ◽  
Epitaxial Thin Films ◽  
Cross Sectional ◽  
Ybco Films ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Edge Dislocations

ABSTRACTHigh quality YBa2Cu3O7–δ, (YBCO) epitaxial thin films grown on MgO substrate with a strainrelieved SrTiO3 (STO) buffer layer have been investigated by Rutherford backscattering spectrometry (RBS), ion channeling and high resolution cross sectional transmission electron microscopy (XTEM). The in-situ growth of STO buffer layer along with the YBCO films was carried out by pulsed laser ablation. In this work, minimum yield of channeling measurements have shown that a very thin STO buffer layer is sufficient to grow highly crystalline YBCO thin films on MgO substrates. TEM studies showed that the STO layers were strain-relieved by an array of periodic edge dislocations. The YBCO films on STO buffer, as in those grown directly on an STO substrate, evolved from a strained layer to a largely dislocation free area.

Microstructure and Strain Relaxation of Epitaxial SrRuO3 Films

1998 ◽  
Vol 4 (S2) ◽  
pp. 580-581
Author(s):  
J. C. Jiang ◽  
X. Q. Pan ◽  
Q. Gan ◽  
C. B. Eom
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Epitaxial Thin Films ◽  
University Of Michigan ◽  
Plan View ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
The University

It is widely believed that the stress in the epitaxial thin films, caused by the lattice mismatch between the thin film and substrate, has a strong influence on the properties. For example, lattice strained epitaxial thin films of SrRu03 grown on (001) SrTiO3 demonstrated magnetic and electrical properties different from those in bulk materials.1 In this paper, we report the effect of strain relaxation of the thin film on microstructure by means of transmission electron microscopy (TEM).SrRuO3 thin film on a vicinal (001) SrTiO3, with a miscut angle 0.9° and miscut direction 5.7° away from the in-plane [100] axis, was grown by 90° off-axis sputtering. Cross-section and plan-view TEM specimens were prepared following the procedure described in Ref. 2. TEM investigations were conducted in a Philips CM 12 microscope in the EMAL at the University of Michigan.X-ray diffraction studies of the as-grown SrRu03 thin film using a four-circle diffractometer showed that the film consists of a single [ 110]-type domain structure.

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