Local Structure of Indium-Plated Porous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
Toshimichi Ito ◽  
Takashi Ooiwa ◽  
Takanobu Nagao ◽  
Akimitsu Hatta
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Porous Silicon ◽  
Thermal Oxidation ◽  
Transmission Electron Microscope ◽  
Local Structure ◽  
Rutherford Backscattering Spectrometry ◽  
Oxidation States ◽  
Si Substrate ◽  
Transmission Electron

AbstractThe fine structure of porous silicon (PS) plated electro-chemically with indium at a low plating charge of 0.03 C/cm2 has been studied mainly using Rutherford backscattering spectrometry and a transmission electron microscope. The results obtained here show (1) that the amount of plated In atoms strongly depends on the oxidation states of the pore surfaces, (2) that the average In densities, the maximum of which is usually located near the PS - Si substrate interface, are typically larger than 1 % of the Si densities in the PS layers, and (3) that the plated In atoms are concentrated locally in pores larger in size. Two-step thermal oxidation of an In-plated PS specimen results in a structure of nm-sized Si crystallites surrounded mainly by Si oxide and In oxide.

Interfacial Reactions of the Pt/Ti/Si Structures

1992 ◽  
Vol 260 ◽  
Author(s):  
Bae-Heng Tseng ◽  
Chong-Kuang Lee ◽  
Ming-Feng Tseng
Keyword(s):  
Electron Microscope ◽  
Solid Solutions ◽  
Transmission Electron Microscope ◽  
Diffusion Barrier ◽  
Depth Profiling ◽  
Interfacial Reactions ◽  
Si Substrate ◽  
Native Oxides ◽  
Ti Oxides ◽  
Transmission Electron

ABSTRACTA 15rm-thick Ti-layer incorporated between Pt and Si was found to be effective in improving the structures of PtSi/Si interface. The roles of Ti-layer were to react with native oxides on the Si substrate and to form Ti-O solid solutions instead of Ti oxides which act as diffusion barrier and inhibit the reactions between Pt and Si. Auger depth profiling gave evidence that Ti and O moved outward as platinum suicides were formed. A smooth PtSi/Si interface was revealed by the transmission electron microscope.

scholarly journals Fine Structure in Multi-Phase Zr8Ni21-Zr7Ni10-Zr2Ni7 Alloy Revealed by Transmission Electron Microscope

Materials ◽  
2015 ◽  
Vol 8 (7) ◽  
pp. 4618-4630 ◽  
Author(s):  
Haoting Shen ◽  
Leonid Bendersky ◽  
Kwo Young ◽  
Jean Nei
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Transmission Electron ◽  
Multi Phase

Nanoscale Pattern Transfer Using Sputter-Induced Corrugations Formed at the Si/SiO2 Interface

2001 ◽  
Vol 705 ◽  
Author(s):  
Cary G. Allen ◽  
Matthew Daniels ◽  
Christopher C. Umbach ◽  
Jack M. Blakely
Keyword(s):  
Electron Microscope ◽  
Aspect Ratio ◽  
Transmission Electron Microscope ◽  
Normal Incidence ◽  
Incidence Geometry ◽  
Pattern Transfer ◽  
Si Substrate ◽  
Ion Etching ◽  
Transmission Electron ◽  
Thermal Oxide

AbstractA conventional ion mill used for thinning transmission electron microscope samples has been used to produce nanoscale surface corrugations on the thermal oxide of Si. Using Ar ions with energies from 1.1 to 2.5 keV in an off-normal incidence geometry, the corrugations were produced with wavelengths from 30 to 80 nm and amplitudes of ~1 to 2 nm. The corrugated pattern in the oxide has been transferred to the underlying Si substrate by reactive ion etching, producing structures that have a much higher aspect ratio than the original corrugations.

The flagellar apparatus in zoospores of Phytophthora, Pythium, and Halophytophthora

1992 ◽  
Vol 70 (11) ◽  
pp. 2163-2169 ◽  
Author(s):  
D. J. S. Barr ◽  
N. L. Désaulniers
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Flagellar Apparatus ◽  
Posterior Root ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Cytoplasmic Microtubules ◽  
Relationship Of ◽  
The Relationship

The flagellar apparatuses of 14 species of Phytophthora, 2 of Halophytophthora, and 4 of Pythium are compared in the transmission electron microscope. Except for Phytophthora infestans and Phytophthora mirabilis there were no significant differences in fine structure morphology. There are six flagellar roots: a ribbed triplet consisting of three main microtubules and secondary microtubules; an anterior doublet; a multistranded, band-shaped root of five to nine microtubules; a posterior root of two to four microtubules; and roots consisting of arrays of cytoplasmic microtubules and nuclear-associated microtubules. In P. infestans and P. mirabilis the multistranded root is missing, the posterior root contains five or six microtubules, and the anterior ribbed root contains four main microtubules. The transitional zones in all species are similar. The relationship of the Pythiaceae with other Oomycetes is discussed. Key words: taxonomy, phytogeny, cytology, Oomycetes, Pythiaceae.

Analysis of Cellular Organelles and Macromolecular Assemblies by Electron Energy Loss Spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 290-291
Author(s):  
R.D. Leapman ◽  
S.B. Andrews
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Energy Loss ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Electron Energy Loss Spectroscopy ◽  
Low Loss ◽  
Macromolecular Assemblies ◽  
Transmission Electron ◽  
Electron Energy Loss

Recent advances in electron energy loss spectroscopy (EELS) have significantly extended the range of applications for biological microanalysis. For example, EELS can now detect physiological concentrations of the important element calcium in rapidly frozen cells with a sensitivity greater than that achievable by energy-dispersive x-ray spectroscopy (EDXS). It can also detect small numbers of phosphorus atoms bound to macromolecular assemblies, and measure water distributions in frozen hydrated tissue. Here we discuss some of these developments in the context of detection limits and mapping techniques in the scanning transmission electron microscope (STEM) and energy-filtering transmission electron microscope (EFTEM).The useful information about elemental composition in EELS of biological specimens generally resides in weak core-edge signals corresponding to atomic concentrations in the 10−5−10−3 (1–100 mmol/kg dry weight) range. For example, the Ca L2,3 signal/background ratio is typically only 10−3 and it is necessary to measure differences in signal that are only 104 of the background. Changes in low-loss fine structure corresponding to varying chemical composition are also very subtle; for example, detection of a 3% change in water content requires reliable measurement of a 0.1 eV shift in the low-loss intensity maximum. To extract such information requires efficient parallel detection of the energy loss spectrum and a high-brightness source to provide a sufficient number of incident electrons. The dedicated STEM is particularly well-suited for analyzing low concentrations of biological elements. If desired, the probe current can be reduced into the picoampere range for low-dose, high-resolution imaging prior to elemental analysis. The STEM’S field-emission source can then be used to deliver a current approaching 10 nA into a ~10 nm diameter probe. High electron flux conditions are ideal for spectrum-imaging applications where adequate counting statistics must be achieved within a limited pixel dwell time. The cold field-emission source of the STEM has the additional advantage of providing electrons with a narrow energy spread of <0.5 eV which is important in fine structure studies.

Lamellae and their organization in melt-crystallized polymers

1994 ◽  
Vol 348 (1686) ◽  
pp. 29-43 ◽  
Keyword(s):  
Fine Structure ◽  
Thermal Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Molecular Mechanisms ◽  
Mechanical And Thermal Properties ◽  
Screw Dislocations ◽  
Transmission Electron ◽  
Gain Material

Significant advances in knowledge of lamellae and their organization in meltcrystallized polymers have stemmed from the ability to examine internal morphologies systematically with the transmission electron microscope. Spherulites form because the first-forming (dominant) lamellae branch repetitively, often at giant screw dislocations, then diverge substantially creating a skeleton to which later-forming lamellae must accommodate. This sequence promotes chain-folding, invites fractional crystallization and modulates chemical, mechanical and thermal properties of spherulites at the inter-dominant spacing. The key feature of lamellar divergence at screw dislocations is present in individual crystals, probably deriving from pressure of uncrystallized molecular cilia; growing lamellae will also distort very substantially to gain material. If necessary, spacefilling is achieved without lamellar and crystallographic continuity by nucleating new growth at large misorientations. Individual melt-grown crystals have been studied both after extraction from a quenched matrix and in situ in thinned specimens. For polyethylene different lamellar profiles have been placed in context while their fine structure provides insights into molecular mechanisms of growth.

Effect of Oxygen Partial Pressure on Formation of Fe2O3 Nanostructure during Thermal Oxidation

2013 ◽  
Vol 734-737 ◽  
pp. 2256-2259 ◽  
Author(s):  
Jing Zhe Wang ◽  
C.H. Xu ◽  
Yu Fei You ◽  
Jun Peng Wang
Keyword(s):  
Electron Microscope ◽  
Surface Morphology ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Thermal Oxidation ◽  
Transmission Electron Microscope ◽  
Pure Oxygen ◽  
Transmission Electron ◽  
Ceramic Crucible ◽  
Effect Of Oxygen

In this paper, effect of oxygen partial pressure on formation of Fe2O3 nanostructure during Thermal Oxidation was studied. Fe2O3 nanostructure was formed by controlling oxidation conditions (Po2) and using the method of thermal oxidation. To begin with, a piece of pure iron in a ceramic crucible was put in the tube furnace (SYS-G-Z-13). Next the metallic Fe was oxidized at 500°C for 4 hours, under different oxygen partial pressure including pure argon (Po2 = 0atm), air Po2 = 0.21atm) and pure oxygen (Po2 = 1atm) to produce nanostructure, respectively. The surface morphology of the oxidized specimens was observed by SEM. The crystalline structure of the nanostructure was determined by transmission electron microscope. The experimental results show that the density of nanosheets increases with increasing oxygen partial pressure.

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