Sputtered and Reactively Grown Epitaxial GdAIO3 Films as Buffer Layers for C-Oriented YBa2Cu3O7-δ Films on R-Sapphire

1995 ◽  
Vol 401 ◽  
Author(s):  
S. Senz ◽  
H. Sieber ◽  
N. D. Zakharov ◽  
M. Lorenz ◽  
H. Hochmuth ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Sections ◽  
Film Growth ◽  
Buffer Layers ◽  
Orientation Relationships ◽  
Ybco Films ◽  
Transmission Electron ◽  
20 Nm ◽  
Growth Methods

AbstractThin films of the orthorhombic perovskite GdAlO3 were grown on R-plane sapphire single crystals. Two different film growth methods were used, viz. (i) a chemical reaction of a Gd-O plasma with the sapphire crystals, and (ii) the reactive radio frequency (r.f.) sputtering of a GdAlO3 target. Subsequently, YBa2Cu3O7-δ (YBCO) films were deposited onto the GdAlO3 buffer by pulsed laser deposition (PLD). The GdAlO3 and YBCO films were investigated by Xray diffraction pole figure analysis and transmission electron microscopy (TEM), including highresolution transmission electron microscopy of cross sections. Independent of the deposition method the GdAlO3 films grew according to the nearly equivalent orientation relationships The GdAlO3 grains are additionally tilted by angles up to ± 3° around the sapphire [11.1] axis. On top of these buffer layers the YBCO films grew with c-orientation and with an in-plane rotation of 45°. YBCO films of 200 nm thickness on GdAlO3 buffer layers with a thickness of 10 to 20 nm showed a Tc > 87 K and a jc(77 K) > 3×106 A/cm2.

Characterization of pulsed laser deposited PbO/MoS2 by transmission electron microscopy

1994 ◽  
Vol 9 (1) ◽  
pp. 236-245 ◽  
Author(s):  
S.D. Walck ◽  
M.S. Donley ◽  
J.S. Zabinski ◽  
V.J. Dyhouse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sodium Chloride ◽  
Room Temperature ◽  
Film Growth ◽  
Composite Films ◽  
Pulsed Laser ◽  
Two Phase ◽  
Transmission Electron ◽  
20 Nm

Films of PbO/MoS2, grown by pulsed laser deposition, exhibit a significant improvement in tribological performance compared to MoS2 films grown by the same process. The microstructure and crystallography of PbO/MoS2 composite films were investigated using transmission electron microscopy (TEM) to identify the features responsible for this tribological improvement. Self-supporting samples were prepared from pulsed laser deposited, PbO/MoS2 thin films grown on single crystal sodium chloride substrates. Films deposited at room temperature exhibited a two-phase microstructure with one of the phases being amorphous. X-ray microanalysis results showed that the crystalline phase had significantly higher concentration ratios of Mo/Pb, Mo/S, and Pb/S than did the amorphous phase. Films grown at 300 °C were polycrystalline, with a grain size of about 20 nm, and had a NaCl type structure which was isomorphous to PbS. The grains had rectangular shape, and exhibited preferred orientation with the sodium chloride substrate. The concentration of S for these films was approximately 80% of the S concentration for films grown at room temperature. Both the high temperature and room temperature films had S concentrations which were higher than expected from the MoS2 in the target; this was attributed to gettering of the S in the vacuum chamber by Pb. The electron diffraction results, together with previously published results, suggest that the crystal structure of the phases in these films is not responsible for the improvement in tribological properties. However, the microstructural components formed during film growth do determine the wear-induced chemical reaction pathways.

Transmission electron microscopy study of YNi2B2C thin film growth on MgO(001)

2004 ◽  
Vol 19 (5) ◽  
pp. 1413-1416 ◽  
Author(s):  
G.H. Cao ◽  
P. Simon ◽  
W. Skrotzki
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Growth ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Orientation Relationships ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Mgo Substrate

A YNi2B2C thin film deposited on MgO(001) substrate by pulsed laser deposition has been investigated by transmission electron microscopy (TEM). Cross-sectional TEM analyses show that the YNi2B2C film grows in the [001] direction. Y2O3 exists not only as an interlayer at the interface of the YNi2B2C thin film and the MgO substrate but occasionally also in the YNi2B2C thin film near the substrate. The orientation relationships between the YNi2B2C thin film, Y2O3 interlayer, and MgO substrate are determined from electron-diffraction patterns to be MgO(001)[100] ‖ Y2O3(001)[100], YNi2B2C(001)[110] ‖ Y2O3(001)[100] ‖ Y2O3(001)[100, and YNi2B2C(001)[100] ‖ Y2O3(001)[100 1.5‖ Y2O3(001)[100] ‖ Y2O3(001)[100 (the numeral above the “parallel” symbol represents the misorientation (in degrees) between the [100] ‖ Y2O3(001)[100 directions).

scholarly journals Transmission Electron Microscopy Study of Thick Copper-304 Stainless Steel Multilayers

1993 ◽  
Vol 311 ◽  
Author(s):  
M. A. Wall ◽  
T. W. Barbee ◽  
T. Weihs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
304 Stainless Steel ◽  
Orientation Relationships ◽  
Plan View ◽  
Transmission Electron ◽  
Bcc Structure ◽  
20 Nm ◽  
Fcc Structure

ABSTRACTThick (10 to 25 μm), free-standing, equal layer thickness, Copper(Cu)-304 Stainless Steel(SS) multilayer foils, having periods of lnm to 100 nm, synthesized by magnetron sputter deposition, have been examined by plan view and cross-sectional transmission electron microscopy. Multilayer growth morphology, individual layer structure and crystallographic phase orientation relationships were characterized in this study. Electron Energy Loss filtered imaging of a 20 nm period multilayer cross-section was also performed and showed that nickel had diffused into the Cu layers from the SS during synthesis. X-ray powder diffraction scans were performed and analyzed. A pure deposit of 304SS was synthesized and had a metastable BCC structure. Multilayer samples having periods of 20 nm were found to have a coherent layered Cu(FCC)- SS(FCC) structure. At larger periods (50 & 100 nm) a bimodal Cu(FCC)-SS(FCC & BCC) structure was formed. These observations show that the 304SS will grow with a metastable BCC structure when sputter deposited. When layered with Cu(FCC) the 304SS has its equilibrium FCC structure at layer thicknesses up to 10nm as a result of epitaxy with the copper. At larger SS layer thicknesses the SS appears to locally transform to the metastable BCC structure during synthesis, refining the grain structure of the depositing SS layer and the subsequent Cu layer. This transformation significantly increases the strength of the larger period multilayer.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

scholarly journals Transmission electron microscopy analysis of the crystallography of precipitates in Mg–Sn alloys aged at high temperatures

2014 ◽  
Vol 47 (5) ◽  
pp. 1729-1735 ◽  
Author(s):  
Xin Nie ◽  
Yimin Guan ◽  
Dongshan Zhao ◽  
Yu Liu ◽  
Jianian Gui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Dark Field ◽  
Peak Hardness ◽  
Invariant Line ◽  
Orientation Relationships ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Annular Dark Field

The crystallographic orientation relationships (ORs) of precipitated β-Mg2Sn particles in Mg–9.76 wt% Sn alloy aged at 573 K for 5 h, corresponding to its peak hardness, were investigated by advanced transmission electron microscopy (TEM). OR-3 of (110)β//(0001)αand [\overline 111]β//[1\overline 210]αand OR-4 of (110)β//(0001)αand [001]β//[2\overline 1\overline 10]αare the key ORs of β-Mg2Sn particles in the alloy. The proportions of β-Mg2Sn particles exhibiting OR-3 and OR-4 were determined as 75.1 and 24.3%, respectively. Crystallographic factors determined the predominance of OR-3 in the precipitated β-Mg2Sn particles. This mechanism was analyzed by a three-dimensional invariant line model constructed using a transformation matrix in reciprocal space. Models of the interface of precipitated β-Mg2Sn and the α-Mg matrix were constructedviahigh-resolution TEM and atomic resolution high-angle annular dark-field scanning TEM.

Enamel Crystal Shape: History of an Idea

1987 ◽  
Vol 1 (2) ◽  
pp. 322-329 ◽  
Author(s):  
H. Warshawsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Sections ◽  
Three Dimensional ◽  
Unit Cell ◽  
Cross Sectional ◽  
Transmission Electron ◽  
History Of ◽  
Sectional Shape ◽  
Imaging Plane

The purpose of this paper is to review evidence which casts doubt on the interpretation universally applied to hexagonal images seen in sectioned enamel. The evidence is based on two possible models to explain the hexagonal profiles seen in mammalian enamel with transmission electron microscopy. The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons. The "rectangular ribbon" model proposes that hexagonal profiles are caused by three-dimensional segments that are parallelepipeds contained in the Epon section. Since shadow projections of such rectangular segments give angles that are inconsistent with the hexagonal unit cell, a model based on ribbons with rhomboidal cut ends and angles of 60 and 120° is proposed. The "rhomboidal ribbon" model projects shadows with angles that are predicted by the unit cell. It is suggested that segments of such crystallites in section project as opaque hexagons on the imaging plane in routine transmission electron microscopy. Morphological observations on crystallites in sections - together with predictions from the hexagonal, rectangular, and rhomboidal ribbon models - indicate that crystallites in rat incisor enamel are flat ribbons with rhomboidal cross-sectional shape. Hexagonal images in electron micrographs of thin-sectioned enamel can result from rhomboidal-ended, parallelepiped-shaped segments of these crystallites projected and viewed as two-dimensional shadows.

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