Atomic Scale Interfacial Structure of Hydroxyapatite Observed with High-Resolution Transmission Electron Microscopy

2000 ◽  
Vol 192-195 ◽  
pp. 283-286 ◽  
Author(s):  
Kimiyasu Sato ◽  
Toshihiro Kogure ◽  
Toshiyuki Ikoma ◽  
Yuri Kumagai ◽  
M. Tanaka
1994 ◽  
Vol 357 ◽  
Author(s):  
A. J. Pedraza ◽  
Siqi Cao ◽  
L. F. Allard ◽  
D. H. Lowndes

AbstractA near-surface thin layer is melted when single crystal alumina (sapphire) is pulsed laserirradiated in an Ar-4%H2 atmosphere. γ-alumina grows epitaxially from the (0001) face of axalumina (sapphire) during the rapid solidification of this layer that occurs once the laser pulse is over. Cross sectional high resolution transmission electron microscopy (HRTEM) reveals that the interface between unmelted sapphire and γ-alumina is atomistically flat with steps of one to a few close-packed oxygen layers; however, pronounced lattice distortions exist in the resolidified γ-alumina. HRTEM also is used to study the metal-ceramic interface of a copper film deposited on a laser-irradiated alumina substrate. The observed changes of the interfacial structure relative to that of unexposed substrates are correlated with the strong enhancement of film-substrate bonding promoted by laser irradiation. HRTEM shows that a thin amorphous film is produced after irradiation of 99.6% polycrystalline alumina. Formation of a diffuse interface and atomic rearrangements that can take place in metastable phases contribute to enhance the bonding strength of copper to laser-irradiated alumina.


1993 ◽  
Vol 32 (Part 1, No. 6A) ◽  
pp. 2824-2831 ◽  
Author(s):  
Nobuyuki Ikarashi ◽  
Masaaki Tanaka ◽  
Toshio Baba ◽  
Hiroyuki Sakaki ◽  
Koichi Ishida

2009 ◽  
Vol 24 (1) ◽  
pp. 192-197 ◽  
Author(s):  
G.M. Cheng ◽  
Y.X. Tian ◽  
L.L. He

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.


1998 ◽  
Vol 05 (03n04) ◽  
pp. 739-745
Author(s):  
Tokushi Kizuka

The atomic processes in mechanical interaction were visualized by time-resolved high resolution transmission electron microscopy at a spatial resolution of 0.2 nm and a time resolution of 1/60 s. Nanometer-sized tips of gold were approached, contacted, bonded, deformed and fractured inside a 200 kV electron microscope using a piezo-driving specimen holder. The crystallographic boundary formed after the contact. A few layers near the surfaces and bonding boundaries were responsible for the approach, contact and bonding processes. Atomic scale mechanical tests, such as the friction test, compressing, tensile and shear deformation tests, were proposed. A new type of mechanical processing at one-atomic-layer resolution was demonstrated. Atomic scale contact or noncontact type surface scanning similar to that in atomic force microscopy was also performed with the gold tips.


1990 ◽  
Vol 183 ◽  
Author(s):  
R. Hull ◽  
Y. F. Hsieh ◽  
K. T. Short ◽  
A. E. White ◽  
D. Cherns

AbstractWe report observations of interfacial structure and consequences for layer synthesis modes in mesotaxial Si/CoSi2/Si structures, as deduced from high resolution transmission electron microscopy (HRTEM). It is argued that relative crystal misalignments arising from the lattice parameter mismatch between the Si and CoSi2 may render classic rigid shift measurements of interfacial structure inaccurate. An alternative method for determining interfacial structure at threedimensional precipitates by analyzing crystal stacking sequences is demonstrated.


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