Effect of Dopant Concentration on the Growth of Oxide Precipitates in Silicon

1984 ◽  
Vol 36 ◽  
Author(s):  
Satoru Matsumoto ◽  
Ichiro Ishihara ◽  
Hiroyuki Kaneko ◽  
Hirofumi Harada ◽  
Takao Abe
Keyword(s):  
Electron Microscopy ◽  
Doping Concentration ◽  
Dopant Concentration ◽  
The Other ◽  
Boron Doped ◽  
Transmission Electron ◽  
Precipitate Growth ◽  
Doped Silicon ◽  
Phosphorus Doped ◽  
Precipitate Density

ABSTRACTThe dependences of dopant species and concentrations on the growth of oxide precipitates have been studied using transmission electron microscopy. Doping species are phosphorus, antimony and boron. Samples were annealed at 800°C and 850°C for 24∼384hr in dry nitrogen. In phosphorus-doped silicon, the precipitate density is independent of doping concentration and the growth of precipitate obeys the three-quarter power law. The enhancement of the precipitate growth is observed in antimony-doped silicon. On the other hand, the precipitate growth is suppressed in heavily boron-doped silicon as compared with that of lightly boron-doped silicon. This indicates the generation of excess silicon interstitials in heavily boron-doped silicon.

Development of 200 kV Scanning-Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 410-411
Author(s):  
H. Koike ◽  
S. Sakurai ◽  
K. Ueno ◽  
M. Watanabe
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
The Other ◽  
Morphological Observation ◽  
Magnetic Domains ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Increasing Demand

In recent years, there has been increasing demand for higher voltage SEMs, in the field of surface observation, especially that of magnetic domains, dislocations, and electron channeling patterns by backscattered electron microscopy. On the other hand, the resolution of the CTEM has now reached 1 ∼ 2Å, and several reports have recently been made on the observation of atom images, indicating that the ultimate goal of morphological observation has beem nearly achieved.

scholarly journals ZnO Nanoparticles with Controllable Ce Content for Efficient Photocatalytic Degradation of MB Synthesized by the Polyol Method

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Gregorio Flores-Carrasco ◽  
Micaela Rodríguez-Peña ◽  
Ana Urbieta ◽  
Paloma Fernández ◽  
María Eugenia Rabanal
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Doping Concentration ◽  
Polyol Method ◽  
Transmission Microscopy ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Optical Luminescence ◽  
Pl Emission ◽  
Ce Content

This paper reports on the synthesis of Ce-doped ZnO (CZO) nanoparticles (NPs) by an alternative polyol method at low temperature. The method, facile and rapid, uses acetate-based precursors, ethylene glycol as solvent, and polyvinylpyrrolidone as capping agent. The effects of the Ce-doping concentration (ranging from 0 to 8.24 atomic%) on the structural, morphological, compositional, optical, luminescence, and photocatalytic properties of the NPs were investigated by several techniques. The structural findings confirmed that the CZO NPs have a typical hexagonal wurtzite-type structure with a preferred orientation along the (101) plane. The results obtained by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) revealed that the NPs size decreased (from ~30 to ~16 nm) with an increase in the Ce-doping concentration. Energy Dispersive X-Ray Spectroscopy (EDS) and High Resolution Transmission Microscopy (HRTEM) results confirmed the incorporation of Ce ions into the ZnO lattice. Ce-doping influences the photoluminescence (PL) emission compared to that of pure ZnO. The PL emission is related to the presence of different kinds of defects, which could take part in charge transfer and/or trapping mechanisms, hence playing an essential role in the photocatalytic activity (PCA). In fact, in this work we report an enhancement of PCA as a consequence of Ce-doping. In this sense, the best results were obtained for samples doped with 3.24 atomic%, that exhibited a photocatalytic degradation efficiency close to 99% after 60 min ultraviolet (UV) illumination, thus confirming the viability of Ce-doping for environmental applications.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

Comparative morpho-anatomical studies of the female gonoduct within the Pratylenchidae (Nematoda: Tylenchina)

Nematology ◽  
2003 ◽  
Vol 5 (2) ◽  
pp. 293-306 ◽  
Author(s):  
Gaëtan Borgonie ◽  
Wim Bert ◽  
Ruben Van Gansbeke ◽  
Etienne Geraert ◽  
Myriam Claeys
Keyword(s):  
Electron Microscopy ◽  
Germ Cells ◽  
The Other ◽  
Radopholus Similis ◽  
Cell Extension ◽  
Anatomical Studies ◽  
Transmission Electron ◽  
Wall Cell ◽  
Ovarian Wall ◽  
Nacobbus Aberrans

AbstractThe cellular morphology of the gonoduct of six Pratylenchus species, three Pratylenchoides species, Radopholus similis, Zygotylenchus guevarai, Hirschmanniella loofi and Nacobbus aberrans was revealed by dissection and light microscopy. Except for Nacobbus aberrans, all studied species show an overall similarity in gonoduct construction, i.e., an ovary often ending with a ring of cells, an oviduct formed from two rows of four cells and a 12-celled spermatheca followed by a tricolumella containing 16-24 cells. Pratylenchoides magnicauda and Z. guevarai did not diverge from the other Pratylenchidae in this respect, although their gonoduct differs from that of Amplimerlinius and Meloidogyne, both formerly postulated as related genera. The spermatheca structure observed in N. aberrans has not been reported elsewhere in the Nematoda, although the uterus is similar to that reported within the Heteroderinae and Meloidogyninae and the uterus comprises more than 300 cells, enlarging from a tricolumella to a polycolumella. Transmission electron microscopy of Z. guevarai revealed details of the cytoplasmatic contact between epithelial cells and the germ cells; a finger-like ovarian wall cell extension was found penetrating the oocyte. The oviduct lacks a preformed lumen and comprises eight cells with highly plicated cell membranes. The spermatheca is constructed from flattened wall cells and is followed by columnar uterus cells where evidence of eggshell formation was demonstrated.

Sporophytes, megaspores, and massulae of Azolla stanleyi from the Paleocene Joffre Bridge locality, Alberta

1994 ◽  
Vol 72 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Georgia L. Hoffman ◽  
Ruth A. Stockey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Red Deer ◽  
The Other ◽  
Evolutionary Trends ◽  
Reproductive Structures ◽  
Transmission Electron ◽  
New Material

Several hundred vegetative and fertile specimens of Azolla Lam. have been recovered from the Paleocene Paskapoo Formation at the Joffre Bridge locality (Middle Tiffanian (Ti3) age) near Red Deer, Alberta. The spore complexes closely resemble those of the Paleocene A. stanleyi Jain & Hall, and the vegetative material is referred to that species. The specimens are unusually complete in that the remains of the fragile sporophyte are preserved, commonly with reproductive structures in place. Plants reaching up to 2.25 cm in length consist of alternately branched rhizomes bearing alternate, imbricate, sessile leaves. Leaves are ovate with entire margins, papillate surfaces, and a single midvein. Reproductive structures have been examined using light, scanning, and transmission electron microscopy. This new material is compared with the other Paleocene species for which sporophytes are known and discussed in terms of evolutionary trends for the genus. The specimens suggest that most of the vegetative characteristics of modern Azolla species were established by the middle Paleocene. Key words: Azolla, Salviniaceae, megaspore, massula, ultrastructure, Paleocene.

Pollen morphology of Sabinaria magnifica (Cryosophileae, Coryphoideae, Arecaceae)

Phytotaxa ◽  
2015 ◽  
Vol 207 (1) ◽  
pp. 135 ◽  
Author(s):  
Giovanni Raul Bogota ◽  
Carina Hoorn ◽  
Wim Star ◽  
Rob Langelaan ◽  
Hannah Banks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
The Other ◽  
Transmission Electron ◽  
Palm Species ◽  
Scanning Electron

Sabinaria magnifica is so far the only known species in the recently discovered tropical palm genus Sabinaria (Arecaceae). Here we present a complete description of the pollen morphology of this palm species based on light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We also made SEM-based comparisons of Sabinaria with other genera within the tribe Cryosophileae. Pollen grains of Sabinaria magnifica resemble the other genera in the heteropolar, slightly asymmetric monads, and the monosulcate and tectate exine with perforate surface. Nevertheless, there are some clear differences with Thrinax, Chelyocarpus and Cryosophila in terms of aperture and exine. S. magnifica differs from its closest relative, Itaya amicorum, in the exine structure. This study shows that a combination of microscope techniques is essential for the identification of different genera within the Cryosophileae and may also be a necessary when working with other palynologically less distinct palm genera. 

scholarly journals Quantitative In-Situ Nanoindentation of Thin Films in a Transmission Electron Microscope

2001 ◽  
Vol 7 (S2) ◽  
pp. 912-913
Author(s):  
A.M. Minorl ◽  
E.A. Stach ◽  
J.W. Morris
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Real Time ◽  
Silicon Substrates ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Transmission Electron ◽  
Diamond Indenter ◽  
Force Calibration

A unique in situ nanoindentation stage has been built and developed at the National Center for Electron Microscopy in Berkeley, CA. By using piezoceramic actuators to finely position a 3-sided, boron-doped diamond indenter, we are able to image in real time the nanoindentation induced deformation of thin films. Recent work has included the force-calibration of the indenter, using silicon cantilevers to establish a relationship between the voltage applied to the piezoactuators, the displacement of the diamond tip, and the force generated.In this work, we present real time, in situ TEM observations of the plastic deformation of Al thin films grown on top of lithographically-prepared silicon substrates. The in situ nanoindentations require a unique sample geometry (see Figure 1) in which the indenter approaches the specimen normal to the electron beam. in order to meet this requirement, special wedge-shaped silicon samples were designed and microfabricated so that the tip of the wedge is sharp enough to be electron transparent.

Effects of Dopants on the Nucleation and Growth of NiSi2 on Silicon

1987 ◽  
Vol 94 ◽  
Author(s):  
S. W. Lu ◽  
C. W. Nieh ◽  
J. J. Chu ◽  
L. J. Chen
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Low Temperatures ◽  
Nucleation And Growth ◽  
The Other ◽  
Size Factor ◽  
Atomic Size ◽  
Nickel Thin Films ◽  
Transmission Electron

ABSTRACTThe influences of implantation impurities, including BF2, B, F, As and P on the formation of epitaxial NiSi2 in nickel thin films on ion-implanted silicon have been investigated by transmission electron microscopy.The presence of BF2, B, and F atoms was observed to promote the epitaxial growth of NiSi2 at low temperatures. Little or no effect on the formation of NiSi2 was found in samples implanted with As or P ions.The results indicated that the influences of the implantation impurities are not likely to be electronic in origin. Good correlation, on the other hand, was found between the atomic size factor and resulting stress and NiSi2 epitaxy at low temperatures.

scholarly journals Determination of Displacement Fields at the Sub-Nanometric Scale

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1804
Author(s):  
Cesar A. Sciammarella ◽  
Federico M. Sciammarella ◽  
Luciano Lamberti
Keyword(s):  
Electron Microscopy ◽  
Theoretical Models ◽  
The Other ◽  
Nanometer Scale ◽  
Displacement Fields ◽  
Eulerian Description ◽  
Transmission Electron ◽  
Displacement Information ◽  
Crystalline Array

Macroscopic behavior of materials depends on interactions of atoms and molecules at nanometer/sub-nanometer scale. Experimental mechanics (EM) can be used for assessing relationships between the macro world and the atomic realm. Theoretical models developed at nanometric and sub-nanometric scales may be verified using EM techniques with the final goal of deriving comprehensive but manageable models. Recently, the authors have carried out studies on EM determination of displacements and their derivatives at the macro and microscopic scales. Here, these techniques were applied to the analysis of high-resolution transmission electron microscopy patterns of a crystalline array containing dislocations. Utilizing atomic positions as carriers of information and comparing undeformed and deformed configurations of observed area, displacements and their derivatives, as well as stresses, have been obtained in the Eulerian description of deformed crystal. Two approaches are introduced. The first establishes an analogy between the basic crystalline structure and a 120° strain gage rosette. The other relies on the fact that, if displacement information along three directions is available, it is possible to reconstruct the displacement field; all necessary equations are provided in the paper. Remarkably, the validity of the Cauchy-Born conjecture is proven to be correct within the range of observed deformations.

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