Transmission Electron Microscopy (TEM) Studies of Interfaces in TiB2-ZrO2 Composites

1996 ◽  
Vol 458 ◽  
Author(s):  
S. Stemmer ◽  
J. Vleugels ◽  
O. Van Der Biest
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Chemical Reactions ◽  
Reaction Products ◽  
Transformation Toughening ◽  
Transmission Electron ◽  
Interphase Boundaries ◽  
Reaction Zones

ABSTRACTTEM studies of the microstructure and of chemical reactions at interfaces in TiB2-ZrO2 composites are presented. Samples with 70 vol% of Y2O3-stabilized ZrO sintered at 1700 °C showed reaction zones around the TiB2 grains, that consisted of a solid-solution of TiO2 and ZrO2(Y2O3). In addition, nontransformable, tetragonal t'-ZrO2 was observed in these samples. In contrast, the interphase boundaries in composites sintered at 1450 °C contained no reaction products, and the ZrO2 matrix consisted of small, transformable tetragonal grains, as required for transformation toughening of the composites.

Microtexture of shock reaction products of niobium and silica mixtures

1999 ◽  
Vol 14 (7) ◽  
pp. 3169-3174 ◽  
Author(s):  
Reiko Murao ◽  
Masae Kikuchi ◽  
Kiyoto Fukuoka ◽  
Eiji Aoyagi ◽  
Toshiyuki Atou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Shock Compression ◽  
Pressure Range ◽  
Reaction Products ◽  
Small Particles ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron

Shock compression experiments on powder mixtures of niobium metal and quartz were conducted for the pressure range of 30–40 GPa by a 25-mm single-stage propellant gun. Chemical reaction occurred above 35 GPa, and products were found to be mainly so-called “Cu3Au-type” Nb3Si, which contained a small amount of oxygen. Microtextures of the specimen were examined by scanning and transmission electron microscopy. A field-emission transmission electron microscope was used for energy-dispersive x-ray analysis of microtextures in small particles found in the SiO2 matrix, and various species with different Nb/Si ratio and oxygen content were shown to be produced through the nonequilibrium process of shock compression.

Electron microscopy study of interfacial structure and reaction of Yba2Cu3O7/Y-ZrO2 films on LaAlO3 substrates

1998 ◽  
Vol 13 (6) ◽  
pp. 1485-1491 ◽  
Author(s):  
J. Y. Dai ◽  
F. H. Kaatz ◽  
P. R. Markworth ◽  
D. B. Buchholz ◽  
X. Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Interfacial Reaction ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Interfacial Structure ◽  
Reaction Products ◽  
Transmission Electron

The detailed structure and interfacial reaction of epitaxial Yba2Cu3O7/Y-ZrO2 (YBCO/YSZ) films grown by chemical vapor deposition (CVD) on LaAlO3 (LAO) substrates are investigated by means of high-resolution electron microscopy (HREM), analytical transmission electron microscopy, and scanning transmission electron microscopy (STEM). The epitaxial relations of YBCO/YSZ/LAO are [100]YBCO // [110]YSZ // [100]LAO and (001)YBCO // (001)YSZ // (001)LAO. The optimum atomic configuration at the YSZ/LAO interface, in which oxygen is the first atomic layer on LAO, is proposed by using HREM combined with image simulation based on the atomic structure models of the interface. Near the YBCO/YSZ interface, two localized interfacial reaction products are formed: (i) a Y-rich modulated ZrO2 structure at the surface of the YSZ film, which may be caused by the diffusion of Y into the YSZ grains; (ii) an intergranular BaZrO3 phase formed by the diffusion of Ba along the columnar grain boundaries of the YSZ film during YBCO growth.

Transmission Electron Microscope Study of Interfacial Reactions in Gold-Germanium Contact to Gallium Arsenide

1985 ◽  
Vol 54 ◽  
Author(s):  
Taeil Kim ◽  
D.D.L. Chung
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Electron Microscope Study ◽  
Lattice Match ◽  
Perfect Lattice ◽  
Transmission Electron ◽  
Transmission Electron Microscope Study

ABSTRACTThe structure of 500 Å Au/500 A Ge/500 Å Au/GaAs (100) was studied by transmission electron microscopy after annealing at 350 – 500°C. Annealing at 350 – 450°C caused the formation of AuGeAs with a (110) texture, but this phase disappeared after annealing at 500°C. The hexagonal a-AuGa (or AuGa) was formed after annealing at 400°C, such that (111)Au // (0001)a, and [110]AU // [1120]a and there was perfect lattice match between Au (i.e., Au-rich solid solution) and a-AuGa. After annealing at 450°C or above, a phase tentatively identified as the hexagonal Au3Ga was formed and Ge (i.e., Ge-rich solid solution) became epitaxial to (100) GaAs. Annealing at 400°C caused Au to change from no texture to a (110) texture.

Orientation relationship and interfacial structure between Nbsolid solution precipitates and α-Nb5Si3 intermetallics

2009 ◽  
Vol 24 (1) ◽  
pp. 192-197 ◽  
Author(s):  
G.M. Cheng ◽  
Y.X. Tian ◽  
L.L. He
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Stress Concentration ◽  
High Resolution ◽  
Orientation Relationship ◽  
Interfacial Structure ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem

The orientation relationship (OR) and the interfacial structure between Nb solid solution (Nbss) precipitates and α-Nb5Si3 intermetallics have been investigated by transmission electron microscopy (TEM). The OR between Nbss and α-Nb5Si3 was determined by selected-area electron diffraction analyses as (222)Nb//(002)α and . High-resolution TEM images of the Nbss/α-Nb5Si3 interface were presented. Steps existed at the interface that acted as centers of stress concentration and released the distortion of lattices to decrease the interfacial energy. In addition, the interfacial models were proposed based on the observed OR to describe the atomic matching of the interface. The distribution of alloying elements at the Nbss/α-Nb5Si3 interface has also been investigated, and Hf was enriched at the interface to strengthen the grain boundary.

Transmission electron microscopy on metal–organic frameworks – a review

2017 ◽  
Vol 5 (29) ◽  
pp. 14969-14989 ◽  
Author(s):  
Christian Wiktor ◽  
Maria Meledina ◽  
Stuart Turner ◽  
Oleg I. Lebedev ◽  
Roland A. Fischer
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spatial Distribution ◽  
Chemical Reactions ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Transmission Electron ◽  
Metal Organic ◽  
Surface Facets

Versatile materials like MOFs require careful characterization. TEM can be used to determine and identify the crystal structure and surface facets of MOFs, the spatial distribution of guests or building blocks in them and how they are changed in chemical reactions.

scholarly journals Эволюция микроструктуры и системы частиц Ti-=SUB=-3-=/SUB=-Ni-=SUB=-4-=/SUB=- при термообработках нанокристаллического сплава Ti-50.9 at.% Ni

2019 ◽  
Vol 89 (4) ◽  
pp. 534
Author(s):  
Т.М. Полетика ◽  
С.Л. Гирсова ◽  
А.И. Лотков ◽  
К.В. Круковский
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Nanocrystalline Alloy ◽  
Tini Alloy ◽  
Subgrain Structure ◽  
Solid Solution Decomposition ◽  
Transmission Electron

AbstractThe structure of a Ti−(50.9 at % Ni) nanocrystalline alloy is studied by transmission electron microscopy after annealing at 300−500°C. It is found that B2-TiNi solid solution decomposition according to a heterogeneous mechanism with formation of Ti_3Ni_4 particles develops in the subgrain structure and is suppressed in nanograins. The regularities of recovery, polygonization, and recrystallization in the grain/subgrain structure of a nanocrystalline TiNi alloy are established and their interconnection with processes of dissolution and coagulation of Ti_3Ni_4 particles is identified.

Epitaxially induced secondary grain growth in Ti:LiNbO3 optical waveguides

1989 ◽  
Vol 47 ◽  
pp. 424-425
Author(s):  
M. A. McCoy
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Refractive Index ◽  
Lithium Niobate ◽  
Grain Growth ◽  
Optical Waveguides ◽  
Waveguide Devices ◽  
Transmission Electron ◽  
Electro Optic

Lithium niobate (LiNbO3) is one of the most promising materials for use in hybrid optical waveguide devices because of its high electro-optic coefficient and its availability as large single crystals. Optical waveguides in LiNbO3 are most commonly made by Ti indiffusion in which strips of Ti metal (between 10 and 100 nm thick) are deposited on a single crystal LiNbO3 substrate. The device is then heated to temperatures around 1000°C typically for 6 hours. During this time, the Ti diffuses into the LiNbO3 to form a Ti-rich LiNbO3 solid solution. This solid solution has a higher refractive index than the substrate and forms the waveguide region. Factors controlling the indiffusion process, however, are not very well understood and very little is known about the microstructural changes which occur during Ti indiffusion. In this study, the microstructure of Ti:LiNbO3 optical waveguides was examined as a function of time and temperature using transmission electron microscopy (TEM).

Sign in / Sign up

Export Citation Format

Share Document