Interfacial Structure of In/Pt/GaAs Heterojunction Ohmic Contacts

1985 ◽  
Vol 54 ◽  
Author(s):  
D. C. Marvin ◽  
N. A. Ives ◽  
M. S. Leung
Keyword(s):  
Ohmic Contacts ◽  
Interfacial Structure ◽  
Energy Dispersive ◽  
Morphological Properties ◽  
X Ray ◽  
Edx Analysis ◽  
Uniform Interface

ABSTRACTGraded heterojunction InGaAs ohmic contacts to n-GaAs have been prepared which show improved electrical and morphological properties compared with other diffused contacts. The improvements result primarily from the use of a thin 400 A Pt layer between the 4000 Â In layer and the substrate to control the reaction of the In and the GaAs. A study of chemically etched samples using energy dispersive x-ray (EDX) analysis has revealed the formation of a smooth In Ga, As heterojunction interface. Evidence is also presented that the heterojunction regions are epitaxial. A smooth, uniform interface of this type is not formed in other diffused contact systems, such as In/GaAs and Ni/Au-Ge/GaAs.

Thin-section, freeze-fracture, and energy dispersive x-ray analysis studies of the protein bodies of tomato seeds

1980 ◽  
Vol 58 (6) ◽  
pp. 699-711 ◽  
Author(s):  
Ernest Spitzer ◽  
John N. A. Lott
Keyword(s):  
Freeze Fracture ◽  
Protein Body ◽  
Cell Types ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
Elemental Content ◽  
Tomato Seed ◽  
Endosperm Tissue ◽  
X Ray ◽  
Edx Analysis

Protein bodies of dry seeds of tomato (Lycopersicon esculentum) from radicle, hypocotyl, cotyledon, and endosperm tissue were extensively studied using thin-sectioning, freeze-fracturing and energy dispersive x-ray (EDX) analysis. Protein bodies varied in size, were oval to circular in section, and generally consisted of a proteinaceous matrix, globoid crystal, and protein crystalloid components. Size, shape, and arrangements of globoid crystals and protein crystalloids varied even within the same cell. Globoid crystals were generally oval to circular in section. They were always surrounded by a proteinaceous matrix. In a given protein body the number present ranged from a few to numerous. A protein body generally contained only one protein crystalloid. In section, protein crystalloids were irregular or angular in shape. They were composed of substructural particles which formed lattice planes. EDX analysis of tomato seed globoid crystals revealed the presence of P, K, and Mg in all cases, a fact that is consistent with globoid crystals being phytin-rich. Rarely, small amounts of calcium were found along with P, K, and Mg in globoid crystals of each of the tissue regions considered. The distribution pattern of cells with Ca containing globoid crystals was random. Small amounts of Fe and Mn were also found in the globoid crystals of protein bodies from certain cell types. These two elements, unlike calcium, were specific in terms of their distribution. Globoid crystals from the protodermal cells often contained Mn and Fe. The globoid crystals from provascular tissue of radicle, hypocotyl, and cotyledon regions often contained Fe while globoid crystals in the first layer of large cells surrounding these provascular areas always contained Fe. Results from EDX analysis of the proteinaceous material from the protein bodies are presented and discussed as are variations in elemental content due to different fixations.

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

scholarly journals A correlative method to quantitatively image trace concentrations of elements by combined SIMS-EDX analysis

2021 ◽  
Author(s):  
Lluís Yedra ◽  
C. N. Shyam Kumar ◽  
Alisa Pshenova ◽  
Esther Lentzen ◽  
Patrick Philipp ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Energy Dispersive ◽  
New Method ◽  
X Ray ◽  
Edx Analysis ◽  
Ion Mass Spectrometry ◽  
Trace Concentrations ◽  
Secondary Ion

The study demonstrates a new method to quantify Secondary Ion Mass Spectrometry (SIMS) images by using a synergetic combination of Energy Dispersive X-ray spectroscopy (EDX) and SIMS.

Atomic Layer Epitaxy of (Si1-xC1-y)Gex+y Layers on 4H-SiC

2006 ◽  
Vol 527-529 ◽  
pp. 1559-1562
Author(s):  
Jörg Pezoldt ◽  
Thomas Kups ◽  
Petia Weih ◽  
Thomas Stauden ◽  
Oliver Ambacher
Keyword(s):  
Molecular Beam Epitaxy ◽  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Ternary Alloys ◽  
Energy Dispersive ◽  
Atomic Layer Epitaxy ◽  
X Ray ◽  
Edx Analysis

3C-(Si1-xC1-y)Gex+y ternary alloys were grown on 8.5° off axis 4H-SiC substrates by solid source molecular beam epitaxy in a temperature range between 750°C and 950°C. Energy dispersive X-ray (EDX) analysis revealed a decrease of the Ge incorporation versus substrate temperature. This effect is due to the fixed Si/Ge ratio during the epitaxial growth. The Ge distribution within the grown epitaxial layers was found to be nearly homogeneous. The investigations by atomic location by channeling enhanced microanalysis allowed the conclusion that Ge is located mainly at Si lattice sites.

An energy dispersive x-ray analysis study of elemental loss from globoid crystals in protein bodies as a result of osmium tetroxide fixation

1978 ◽  
Vol 56 (19) ◽  
pp. 2408-2414 ◽  
Author(s):  
J. N. A. Lott ◽  
J. S. Greenwood ◽  
C. M. Vollmer
Keyword(s):  
Osmium Tetroxide ◽  
Juglans Regia ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
X Ray ◽  
Edx Analysis ◽  
Freeze Dried ◽  
Major Loss ◽  
Degree Of Extraction ◽  
Helichrysum Bracteatum

This study was undertaken to discover what elemental losses, if any, were occurring from globoid crystals in seed protein bodies during glutaraldehyde – osmium tetroxide fixation. Unfixed cotyledon and radicle tissue of Cucurbita maxima seed, or tissue after glutaral–dehyde–OsO4 treatment, was quick frozen in liquid N2, ground with a cold mortar and pestle, and low-temperature freeze-dried. Globoid crystals in the freeze-dried powder were subjected to energy dispersive x-ray (EDX) analysis. OsO4 fixation resulted in a major loss of P, Mg, and K from cotyledon globoid crystals and a major loss of P, Mg, K, and Ca from radicle globoid crystals. Despite the loss of elements, the OsO4-fixed globoid crystals were still electron dense. When globoid crystals from glutaraldehyde-fixed, dehydrated, and embedded cotyledon tissue were compared with globoid crystals from glutaraldehyde–OsO4-fixed, dehydrated, and embedded tissue, some extraction was found. The degree of extraction varied from complete loss of P, K, and Mg to loss of K only.Effects of glutaraldehyde–OsO4 fixation upon elemental composition of globoid crystals in several other species was also determined. Brazil nut (Bertholletia excelsa) radicle tissue or cotyledon tissue from walnut (Juglans regia), hazelnut (Corylus avellana), sunflower (Helianthus annuus), golden everlasting daisy (Helichrysum bracteatum), cashew (Anacardium occidentale), pistachio (Pistacia vera), and the Western Australian red-capped gum (Eucalyptus erythrocorys) were fixed either in glutaraldehyde or in glutaraldehyde–OsO4. In these species, EDX analysis of globoid crystal sections showed that OsO4 fixation results in major loss of Mg, K, and Ca. Generally, phosphorus levels were reduced from control values as well. When carrying out EDX analysis studies of globoid crystals, we recommend (1) avoiding any use of OsO4, (2) keeping all fixation, washing, and dehydration times as short as possible, and (3) checking all observations with freeze-dried powders.

scholarly journals The Development of A Large-Area Windowless Energy Dispersive X-ray Detector for STEM-EDX Analysis

2013 ◽  
Vol 19 (S2) ◽  
pp. 1192-1193 ◽  
Author(s):  
K. Tamura ◽  
R. Namekawa ◽  
R. Buchhold ◽  
B. Hammell ◽  
A. Sandborg ◽  
...  
Keyword(s):  
Energy Dispersive ◽  
Large Area ◽  
X Ray ◽  
Edx Analysis

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

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