Study of Microstructure in SrTiO3/Si by High-resolution Transmission Electron Microscopy

2002 ◽  
Vol 17 (1) ◽  
pp. 204-213 ◽  
Author(s):  
G. Y. Yang ◽  
J. M. Finder ◽  
J. Wang ◽  
Z. L. Wang ◽  
Z. Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Lattice Misfit ◽  
Structural Defects ◽  
Si Substrate ◽  
Substrate Side ◽  
Transmission Electron ◽  
Interfacial Dislocations ◽  
Image Simulations

Microstructure in the SrTiO3/Si system has been studied using high-resolution transmission electron microscopy and image simulations. SrTiO3 grows heteroepitaxially on Si with the orientation relationship given by (001)STO//(001)Si and [100]STO//[110]Si. The lattice misfit between the SrTiO3 thin films and the Si substrate is accommodated by the presence of interfacial dislocations at the Si substrate side. The interface most likely consists of Si bonded to O in SrTiO3. The alternative presentation of Sr and Si atoms along the interface leads to the formation of 2× and 3× Sr configurations. Structural defects in the SrTiO3 thin film mainly consist of tilted domains and dislocations.

In-Situ Transmission Electron Microscopy and Computer Simulation Study of the Kinetics of Oxygen Loss in Yba2Cu3OZ

1989 ◽  
Vol 169 ◽  
Author(s):  
C. P. Burmester ◽  
L. T. Wille ◽  
R. Gronsky ◽  
B. T. Ahn ◽  
V. Y. Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulation Study ◽  
Oxygen Loss ◽  
Domain Structures ◽  
Transmission Electron ◽  
Kinetics Of ◽  
Image Simulations

AbstractHigh resolution transmission electron microscopy during in‐situ quenching of YBa2Cu3Oz is used to study the kinetics of microdomain formation during oxygen loss in this system. Image simulations based on atomic models of oxygen‐vacancy order in the basal plane of this material generated by Monte Carlo calculations are used to interpret high resolution micrographs of the structures obtained by quenching. The observed domain structures agree well with those obtained from the simualtions.

The Structure and Passivation Effects of Double-Positioning Twin Boundaries in CdTe

2005 ◽  
Vol 865 ◽  
Author(s):  
Yanfa Yan ◽  
M.M. Al-Jassim ◽  
K.M. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
First Principles ◽  
Density Functional ◽  
Dangling Bonds ◽  
Twin Boundaries ◽  
Transmission Electron ◽  
Cl Atoms ◽  
Image Simulations

AbstractUsing the combination of high-resolution transmission electron microscopy, first-principles density-functional total-energy calculations, and image simulations, we studied the atomic structure and passivation effects of double-positioning (DP) twin boundaries in CdTe. The DP twin boundaries are found to contain more Te dangling bonds than Cd dangling bonds, resulting in energy states in the bandgap that are detrimental to the electronic properties of CdTe. We found that I, Br, Cl, S, and O atoms present passivation effects on the DP twin boundaries to differing degrees, whereas H does not passivate the boundaries. Of all these impurities, I and Cl atoms present the best passivation effects on the DP twin boundaries. The superior passivation effects are realized by either terminating the Cd atoms with dangling bonds, or substituting the Te atoms with dangling bonds in the DP twin boundaries in CdTe by Cl and I atoms.

scholarly journals Microstructure Evolution in He-Implanted Si at 600 °C Followed by 1000 °C Annealing

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5107
Author(s):  
Zhen Yang ◽  
Zhiping Zou ◽  
Zeyang Zhang ◽  
Yubo Xing ◽  
Tao Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Single Crystal ◽  
Microstructure Evolution ◽  
Cavity Growth ◽  
Stacking Fault ◽  
Structural Defects ◽  
Dislocation Loops ◽  
Transmission Electron

Si single crystal was implanted with 230 keV He+ ions to a fluence of 5 × 1016/cm2 at 600 °C. The structural defects in Si implanted with He at 600 °C and then annealed at 1000 °C were investigated by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The microstructure of an as-implanted sample is provided for comparison. After annealing, rod-like defects were diminished, while tangled dislocations and large dislocation loops appeared. Dislocation lines trapped by cavities were directly observed. The cavities remained stable except for a transition of shape, from octahedron to tetrakaidecahedron. Stacking-fault tetrahedrons were found simultaneously. Cavity growth was independent of dislocations. The evolution of observed lattice defects is discussed.

scholarly journals Detection of crystalline phase in cross-section multilayer thin film by High-Resolution Transmission Electron Microscopy

1989 ◽  
Vol 47 ◽  
pp. 680-681
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Cross Section ◽  
Crystalline Phase ◽  
Glass Slide ◽  
Ion Milling ◽  
Si Substrate ◽  
Plan View ◽  
Transmission Electron

High-resolution transmission electron microscopy has proven to be very useful in direct detection of crystalline phases that exist over extremely small volumes, yielding information about structure, orientation, and, under appropriate circumstances, composition. In this paper, we report the detection of a crystalline phase in the tungsten-rich layer of an annealed 7 nm-period tungsten-carbon multilayer produced at the Center for X-Ray Optics at the Lawrence Berkeley Laboratory.The multilayers were prepared by dc magnetron sputtering at floating temperature. The argon sputter gas pressure was 0.0020 torr. Different techniques were employed to produce cross-section and plan-view samples for TEM. For cross-section samples, 70 bilayers of W and C were sputtered on semiconductor-grade Si (111) wafers. For plan-view samples, the substrates on which the multilayer was grown consisted of 3 mm-diameter 300-mesh copper microscope grids, mounted on glass slide with Crystalbond® vacuum adhesive. After a deposition of 4 bilayers of W-C, keeping the same sputtering parameters as those of the Si substrates to guarantee the same layer thicknesses, the glass slide was soaked in acetone to disolve the Crystalbond®, leaving the multilayer spanning the holes of the copper grids. Both the Si-substrate and copper-grid samples were annealed at 500°C for 4 hours under vacuum of 10−6 torr. The annealed Si-substrate sample was then prepared for cross-section by mechanical grinding, and ion milling in a cold stage at 5kV. The cross-section sample was studied in a JEOL JEM 200CX with ultrahigh resolution goniometer, with the eletron beam parallel to the [112] of the Si substrate. The plan-view sample was studied in a Philips 301 operating at 100kV.

High resolution transmission electron microscopy study of interface structures and growth defects in epitaxial Bi2Sr2Can−1CunO4+2n + δ films on SrTiO3 and LaAlO3

1996 ◽  
Vol 11 (10) ◽  
pp. 2416-2428 ◽  
Author(s):  
N. D. Zakharov ◽  
D. Hesse ◽  
J. Auge ◽  
H. G. Roskos ◽  
H. Kurz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Layer By Layer ◽  
Composite Target ◽  
Substrate Interface ◽  
Dc Sputtering ◽  
Transmission Electron ◽  
Interfacial Dislocations ◽  
Film Substrate

The defect structure of epitaxial, c-oriented Bi2Sr2Can−1CunO4+2n+δ (BSCCO) thin films grown by dc-sputtering and layer-by-layer MBE on SrTiO3 and LaAlO3 single crystal substrates was investigated by high-resolution transmission electron microscopy (HRTEM). Particular emphasis was put on the structure of the film/substrate interface. The films grown by dc-sputtering show a rather perfect structure involving a regular stacking of the unit cells. In spite of this regularity, there are many defects, such as twins, chemical stacking faults, and precipitates, as well as interfacial dislocations accommodating the film/substrate lattice misfit. The MBE-grown films contain twins and interfacial dislocations, but most prominent are precipitates of various size and rather high number density. Composition and structure of the precipitates were analyzed. Interfacial dislocations were found to be located in the films at a distance of up to 3 nm from the film/substrate interface. The experiments showed that the quality of the film/substrate interface in MBE-grown films is considerably higher with respect to smoothness, sharpness, and regularity, if the layer-by-layer MBE process starts with a Sr–O layer instead of a Bi–O layer. This observation is in correspondence to the observed interface structure of the dc-sputtered films, where the first film layer was a Sr–O layer, not a Bi–O layer, in spite of the films being sputtered from a composite target. A structure model of the Bi2Sr2Can−1CunO4+2n+δ/(100)SrTiO3 interface is proposed. The prolonged MBE process was shown to imply a chemical interaction between the SrTiO3 substrate and the growing film, resulting in the formation of Sr-rich phases in the near-interface substrate regions.

Origin of Threefold Periodicity in High-Resolution Transmission Electron Microscopy Images of Thin Film Cubic SiC

1999 ◽  
Vol 5 (6) ◽  
pp. 420-427 ◽  
Author(s):  
U. Kaiser ◽  
A. Chuvilin ◽  
P.D. Brown ◽  
W. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Field Imaging ◽  
Microscopy Images ◽  
Image Simulations

Abstract: High-resolution transmission electron microscopy (HRTEM) images of the [1–10] zone of cubic SiC layers grown by molecular beam epitaxy (MBE) often reveal regions of material exhibiting an unusual threefold periodicity. The same contrast was found in earlier works of Jepps and Page, who attributed this contrast in HRTEM images of polycrystalline SiC to the 9R-SiC polytype. In this report we demonstrate by HRTEM image simulations that the model of the 9R polytype and an alternative twinning model can fit qualitatively the experimental HRTEM images. However, by comparing the fast Fourier transform (FFT) patterns of the experiments and the simulations, as well as by using dark-field imaging, we show unambiguously that only the model of overlapping twinned 3C-SiC crystals fully agrees with the experiments.

Characterization of the (0110) α-Ti/γ-TiH Interface Using High-Resolution Transmission Electron Microscopy (TEM) and Electron Energy Loss Spectroscopy (EELS)

1996 ◽  
Vol 54 ◽  
pp. 108-109
Author(s):  
M. M. Tsai ◽  
J. M. Howe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Hydrogen Atoms ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
High Resolution Images ◽  
Electron Energy Loss ◽  
Image Simulations

Precipitation of γ-TiH in α-Ti-H alloys involves a hcp → fct lattice transformation with hydrogen as an interstitial diffusing element Results obtained from a previous TEM study have shown that the lengthening rate of γ-TiH is diffusionally controlled at 25°C, and possibly interfacially controlled at temperatures of 50°C and higher. Therefore, it is essential to ascertain the presence or absence of hydrogen atoms at the interface. TEM foils from a 800 ppm wt.% Ti-H alloy were analyzed using high-resolution TEM and image simulations in order to determine the effects of hydrogen on high-resolution images of the α-Ti/γ-TiH interface, and EELS was used to determine the whether the hydnde structure was fully formed up to the interface.

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