Study of synthetic hydroxyapatite by the method of high-resolution transmission electron microscopy: Morphology and growth direction

Surface and planar defect structures of γ-Al2O3 nanorods synthesized by the arc-discharge method were studied by means of high-resolution transmission electron microscopy and image simulation. Our investigation showed that there was a high number density of twins in the nanorods. We suggested a possible configuration of {111} twins in γ-Al2O3, and this model fit our experimental result well. In some nanorods, the ordering of nanotwins gave rise to a local hexagonal-like structure. The twinned nanorods were usually enclosed by {100} and {111} facets, and their growth direction was changed from 〈110〉 into 〈111〉. The surface structures of the nanorods confirmed that the {111}-type surface should be more stable.

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Structure and Optical Properties of Si/InAs/Si Layers Grown by MBE on Si Substrate at Different Temperatures

MRS Proceedings ◽

10.1557/proc-618-249 ◽

2000 ◽

Vol 618 ◽

Author(s):

N.D. Zakharov ◽

P. Werner ◽

U. Gösele ◽

R. Heitz ◽

D. Bimberg ◽

...

Keyword(s):

Electron Microscopy ◽

Solid Solution ◽

Transmission Electron Microscopy ◽

Optical Properties ◽

High Resolution ◽

Molecular Beam ◽

Growth Direction ◽

Si Substrate ◽

Transmission Electron ◽

Different Temperatures

ABSTRACTEpitaxial Si/InAs/Si heterostructure grown on (001) Si substrate by molecular beam epitaxy (MBE) and annealed at 800°C, and 880°C were investigated by High Resolution Transmission Electron Microscopy (HRTEM). Extensive interdiffusion at 800°C leads to the formation of an InAs solid solution as well as InAs-enriched regions with extensions of ∼6nm, which exhibit two kinds of ordering. The ordering of InAs molecules occurred, respectively, in {110} planes inclined and parallel to the [001] growth direction. It is attributed to the energy gain from the reduced number of mixed Si-As and Si-In bonds. The sample grown at 800°C shows photoluminescence in the 1.3.µm region, which is tentatively attributed to the recombination of excitons localised in the ordered regions

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Investigation of Phosphorus In-Diffusion and Strain in GaAsP/GaAs Using High-Resolution Transmission Electron Microscopy

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.62.1 ◽

2020 ◽

Vol 62 ◽

pp. 1-7

Author(s):

Wonjae Chang

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Molecular Beam ◽

Growth Direction ◽

Gaas Layer ◽

Strained Layers ◽

Atomic Arrangement ◽

Transmission Electron ◽

Substrate Temperatures

We report our experiments based on the interfaces of a 5-period superlattice, containing GaAsP(3Å)/GaAs (190Å) heterostructures grown by molecular beam epitaxy (MBE). The atomic arrangement at the interfaces of GaAsP/GaAs is investigated using high resolution transmission electron microscopy (HRTEM). Our results indicate that the superlattice was grown coherently with strained layers. We propose that the atomic arrangement at the interface is GaP, assuming that phosphorus incorporation occurs primarily via substitution due to desorption of arsenic at the surface for substrate temperatures above 500°C. The incorporation of phosphorus has been investigated using fast Fourier transform (FFT) patterns and shows a form of strain distribution near the heterointerface. The FFT patterns of the superlattice reveal that strain distributes mostly near the interface and gradually decreases along the direction of growth. Phosphorus diffused into a GaAs layer changes the lattice constant in the growth direction, which reduces strain in the superlattice.

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A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055904 ◽

1982 ◽

Vol 40 ◽

pp. 722-723 ◽

Cited By ~ 1

Author(s):

R. Gronsky

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Computer Simulations ◽

Structural Characteristics ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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