scholarly journals Impact of different types of planar defects on current transport in Indium Phosphide (InP)

2021 ◽  
Author(s):  
Christian Dam Vedel ◽  
Enrico Brugnolotto ◽  
Soren Smidstrup ◽  
Vihar P. Georgiev
Keyword(s):  
Indium Phosphide ◽  
Current Transport ◽  
Planar Defects ◽  
Different Types

Point and planar defects in the iron sulfide compounds Fe1-xS

1984 ◽  
Vol 42 ◽  
pp. 434-435
Author(s):  
Thao A. Nguyen
Keyword(s):  
Low Temperatures ◽  
Direct Evidence ◽  
Iron Sulfide ◽  
Planar Defects ◽  
Selective Area ◽  
Vacancy Ordering ◽  
Different Types ◽  
Lattice Images ◽  
The Subject ◽  
Beam Lattice

It is well known that the large deviations from stoichiometry in iron sulfide compounds, Fe1-xS (0≤x≤0.125), are accommodated by iron vacancies which order and form superstructures at low temperatures. Although the ordering of the iron vacancies has been well established, the modes of vacancy ordering, hence superstructures, as a function of composition and temperature are still the subject of much controversy. This investigation gives direct evidence from many-beam lattice images of Fe1-xS that the 4C superstructure transforms into the 3C superstructure (Fig. 1) rather than the MC phase as previously suggested. Also observed are an intrinsic stacking fault in the sulfur sublattice and two different types of vacancy-ordering antiphase boundaries. Evidence from selective area optical diffractograms suggests that these planar defects complicate the diffraction pattern greatly.

scholarly journals Indium Phosphide-Based Semiconductor Nanocrystals and Their Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Paul Mushonga ◽  
Martin O. Onani ◽  
Abram M. Madiehe ◽  
Mervin Meyer
Keyword(s):  
Indium Phosphide ◽  
Surface Passivation ◽  
Semiconductor Nanocrystals ◽  
Core Size ◽  
The Core ◽  
Colloidal Semiconductor Nanocrystals ◽  
Biological Studies ◽  
Fluorescent Materials ◽  
Different Types ◽  
Heating Up

Semiconductor nanocrystals or quantum dots (QDs) are nanometer-sized fluorescent materials with optical properties that can be fine-tuned by varying the core size or growing a shell around the core. They have recently found wide use in the biological field which has further enhanced their importance. This review focuses on the synthesis of indium phosphide (InP) colloidal semiconductor nanocrystals. The two synthetic techniques, namely, the hot-injection and heating-up methods are discussed. Different types of the InP-based QDs involving their use as core, core/shell, alloyed, and doped systems are reviewed. The use of inorganic shells for surface passivation is also highlighted. The paper is concluded by some highlights of the applications of these systems in biological studies.

Crystal Defects In Gan On (0001) Sapphire

1997 ◽  
Vol 482 ◽  
Author(s):  
Matthew T. Johnson ◽  
Zhigang Mao ◽  
C. Barry Carter
Keyword(s):  
Dark Field ◽  
Crystal Defects ◽  
Growth Surface ◽  
Threading Dislocation ◽  
Defect Structures ◽  
Plan View ◽  
Planar Defects ◽  
Dark Field Imaging ◽  
Inversion Domain ◽  
Different Types

AbstractDefect structures in GaN thin films grown on (0001) sapphire have been studied using a combination of different transmission electron microscopy (TEM) techniques. Two fundamentally different types of defects are found in these films. Planar defects which lie on planes perpendicular to the growth surface are common. In some regions of the films, other planar defects are present which run parallel to the surface of the substrate. The terminology used to describe these different defects varies quite widely in the literature and includes combinations of antiphase (inversion) domain boundaries and stacking faults. The second type of defect is generally referred to as a threading dislocation since many thread through the whole thickness of the film. Dislocations with different Burgers vectors have been identified in this work and in previous studies; these dislocations usually have a component of their Burgers vector lying normal to the (0001) plane. The overall defect structures in these films have been characterized using conventional bright-field and dark-field imaging. The detailed structure of the individual defects have been examined using weak-beam microscopy both in plan view and in cross section. This paper illustrates the different types of defects, both planar and linear, compares them to defects which have been characterized more thoroughly in related materials, and discuss the nomenclature of the different defect configurations.

Different Types of Current Instabilities During Low-Temperature Avalanche Breakdown of p-Germanium

1987 ◽  
Vol 42 (5) ◽  
pp. 441-443
Author(s):  
J. Peinke ◽  
J. Parisi ◽  
A. Mühlbach ◽  
R. P. Huebener
Keyword(s):  
Low Temperature ◽  
Impact Ionization ◽  
Dissipative Structures ◽  
Avalanche Breakdown ◽  
Current Transport ◽  
Transport Behavior ◽  
Highly Nonlinear ◽  
Different Types

The highly nonlinear current transport behavior of extrinsic germanium, electrically driven into distinct parameter regimes of impact-ionization-induced avalanche breakdown at liquidhelium temperatures, shows a variety of temporally unstable dissipative structures. We have observed experimentally three different types of current instabilities.

TEM Characterization of Planar Defects in A Massively Transformed TiAl Alloy

1996 ◽  
Vol 460 ◽  
Author(s):  
X. D. Zhang ◽  
J. M. K. Wiezorek ◽  
M. J. Kaufman ◽  
M. H. Loretto ◽  
H. L. Fraser
Keyword(s):  
Tial Alloy ◽  
Al Alloy ◽  
Planar Defects ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Different Types ◽  
High Resolution Tem ◽  
Diffraction Patterns ◽  
Matrix Domains

ABSTRACTThe microstructure of a massively transformed Ti-49at.%Al alloy has been studied by conventional transmission electron microscopy (CTEM) and high resolution TEM (HREM). A high density of planar defects, namely complex anti-phase domain boundaries (CAPDB) and thermal micro-twins (TMT) have been observed. CTEM images and diffraction patterns showed that two anti-phase related γ-matrix domains were generally separated by a thin layer of a 90°-domain, for which the c-axis is rotated 90° over a common cube axis with respect to those of the γ-matrix domains. HREM confirmed the presence of two crystallographically different types of 90°-do-mains being associated with the CAPDB. Furthermore, interactions between the CAPDB and TMT have been observed. Local faceting of the generally wavy, non-crystallographic CAPDB parallel to the {111}-twinning planes occurred due to interaction with the TMT. The relaxation of the CAPDB onto {111} required diffusion which is proposed to be enhanced locally in the presence of the dislocations associated with the formation of TMT during the massive transformation.

Influence of planar defects on powder diffractograms of fcc metals

2002 ◽  
Vol 17 (4) ◽  
pp. 270-277 ◽  
Author(s):  
A. I. Ustinov ◽  
N. M. Budarina
Keyword(s):  
Powder Diffraction ◽  
Stacking Faults ◽  
Diffraction Peak ◽  
High Concentration ◽  
Planar Defects ◽  
X Ray ◽  
Fcc Metals ◽  
Different Types ◽  
High Degree ◽  
Kinematic Approach

X-ray powder diffractograms from fcc crystals containing high concentration (more than 1%) of planar defects [deformation stacking faults (SF), double deformation SF, twin boundaries (TB)] have been simulated by Monte Carlo method in kinematic approach. It was shown that the characteristics of powder diffraction peak profiles (except peaks with indexes H00) dependent nonmonotonically on PD concentration, during which peak maximums stay in Bragg positions. An addition point to emphasize is that an appearance of TB only in the crystal not affects on position of all peaks. Several types of PD to be occurred simultaneously in the crystal influence on powder diffractograms additively. Peculiarities of the powder diffraction pattern inherent in different types of PD have been revealed to permit predominant PD type to be found with a high degree of accuracy based on experimental data.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Differentiating between different forms of moral obligations

2020 ◽  
Vol 43 ◽  
Author(s):  
Rajen A. Anderson ◽  
Benjamin C. Ruisch ◽  
David A. Pizarro
Keyword(s):  
Moral Character ◽  
Moral Obligations ◽  
Different Types

Abstract We argue that Tomasello's account overlooks important psychological distinctions between how humans judge different types of moral obligations, such as prescriptive obligations (i.e., what one should do) and proscriptive obligations (i.e., what one should not do). Specifically, evaluating these different types of obligations rests on different psychological inputs and has distinct downstream consequences for judgments of moral character.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

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