Time-resolved high-resolution electron microscopy of solid state direct bonding of gold and zinc oxide nanocrystallites at ambient temperature

1997 ◽  
Vol 70 (8) ◽  
pp. 964-966 ◽  
Author(s):  
Tokushi Kizuka ◽  
Kanji Yamada ◽  
Nobuo Tanaka
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Solid State ◽  
High Resolution ◽  
Ambient Temperature ◽  
High Resolution Electron Microscopy ◽  
Time Resolved ◽  
Resolution Electron

Time-resolved high-resolution electron microscopy of structural stability in mgo clusters

1996 ◽  
Vol 54 ◽  
pp. 672-673
Author(s):  
T. Kizuka ◽  
N. Tanaka
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Magnesium Oxide ◽  
Structural Stability ◽  
High Resolution Electron Microscopy ◽  
Video Tape ◽  
Solid State Physics ◽  
Time Resolved ◽  
Resolution Electron ◽  
Structural And Functional Properties

Structure and stability of atomic clusters have been studied by time-resolved high-resolution electron microscopy (TRHREM). Typical examples are observations of structural fluctuation in gold (Au) clusters supported on silicon oxide films, graphtized carbon films and magnesium oxide (MgO) films. All the observations have been performed on the clusters consisted of single metal element. Structural stability of ceramics clusters, such as metal-oxide, metal-nitride and metal-carbide clusters, has not been observed by TRHREM although the clusters show anomalous structural and functional properties concerning to solid state physics and materials science.In the present study, the behavior of ceramic, magnesium oxide (MgO) clusters is for the first time observed by TRHREM at 1/60 s time resolution and at atomic resolution down to 0.2 nm.MgO and gold were subsequently deposited on sodium chloride (001) substrates. The specimens, single crystalline MgO films on which Au particles were dispersed were separated in distilled water and observed by using a 200-kV high-resolution electron microscope (JEOL, JEM2010) equipped with a high sensitive TV camera and a video tape recorder system.

Mg–Ti–spinel formation at the TiN/MgO interface by solid state reaction: Confirmation by high-resolution electron microscopy

1991 ◽  
Vol 6 (8) ◽  
pp. 1744-1749 ◽  
Author(s):  
L. Hultman ◽  
D. Hesse ◽  
W-A. Chiou
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
High Resolution ◽  
Solid State Reaction ◽  
Spinel Phase ◽  
High Resolution Electron Microscopy ◽  
Cation Sublattice ◽  
Spinel Formation ◽  
Spinel Lattice ◽  
Resolution Electron

Mg–Ti–spinel formation along the interface of epitaxial TiN(100) films to MgO(100) substrates has recently been investigated by transmission electron microscopy (TEM) in the diffraction-contrast mode in samples grown at substrate temperatures higher than 800 °C and in such post-annealed at 850 °C. This phenomenon has now been investigated by high resolution electron microscopy of cross-sectional samples, at an acceleration voltage of 300 kV. Emphasis is given to the TiN/spinel and the spinel/MgO interfaces with respect to their structure and morphology. The results obtained confirm the previously drawn conclusions on the atomic mechanism of the solid state reaction during the spinel-forming process: The spinel, which most likely is of the composition Mg2TiO4, forms by counterdiffusion of the cations Ti4+ and Mg2+ in the rigid oxygen frame provided by the fcc oxygen sublattice of MgO. The latter is completely taken over by the spinel lattice. This “host” character of the MgO substrate lattice for the topotaxial growth of the spinel lattice and the coherency of the solid state reaction with respect to the lattices of all the phases involved are demonstrated. Misfit dislocations at the TiN/MgO, TiN/spinel, and the spinel/MgO interfaces, as well as antiphase boundaries of the cation sublattice of the spinel phase, have also been observed.

Time-resolved high-resolution electron microscopy of structural transformation in nanocrystalline ZnO films

1996 ◽  
Vol 54 ◽  
pp. 978-979
Author(s):  
T. Kizuka ◽  
N. Tanaka
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Structural Transformation ◽  
Superplastic Deformation ◽  
Boundary Migration ◽  
High Resolution Electron Microscopy ◽  
Grain Boundary Migration ◽  
Time Resolved ◽  
Resolution Electron

Mechanical properties of polycrystalline materials become anomalous when the grain size and grain boundary length decrease to nanometer scale. For example, ductility and toughness increase significantly in nanometer-grained ceramics (nanocrystalline ceramics). Ductility increases due to appearance of fine-grained-superplastic deformation. Grain boundary migration and interface migration are fundamental processes of the superplastic deformation. Structural transformation of fine grains is a factor which limits the toughness in polycrystalline ceramics because the transformation relaxes internal strain. The behavior of grain boundaries and interfaces, such as diffusion bonding and Czochralski-type crystal growth at ambient temperature, can be analyzed by a time-resolved high-resolution electron microscopy (TRHREM) developed by Kizuka et al.,In the present study, grain boundary migration and successive transformation of crystal structure in nanocrystalline ZnO were investigated by TRHREM.Zinc oxide was vacuum-deposited on air-cleaved (001) surfaces of sodium chloride at 200°C. TRHREM was carried out at room temperature using a 200-kV electron microscope (JEOL, JEM2010) equipped with a high sensitive TV camera and a video tape recorder.

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