scholarly journals Design and Characterization of a Sharp GaAs/Zn(Mn)Se Heterovalent Interface: A Sub-Nanometer Scale View

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1315
Author(s):  
Davide F. Grossi ◽  
Sebastian Koelling ◽  
Pavel A. Yunin ◽  
Paul M. Koenraad ◽  
Grigory V. Klimko ◽  
...  
Keyword(s):  
Magnetic Semiconductor ◽  
Atom Probe ◽  
Growth Conditions ◽  
Nanometer Scale ◽  
Magnetic Impurities ◽  
Znse Layer ◽  
Secondary Ions ◽  
Annealing Step ◽  
Tunnel Microscopy

The distribution of magnetic impurities (Mn) across a GaAs/Zn(Mn)Se heterovalent interface is investigated combining three experimental techniques: Cross-Section Scanning Tunnel Microscopy (X-STM), Atom Probe Tomography (APT), and Secondary Ions Mass Spectroscopy (SIMS). This unique combination allowed us to probe the Mn distribution with excellent sensitivity and sub-nanometer resolution. Our results show that the diffusion of Mn impurities in GaAs is strongly suppressed; conversely, Mn atoms are subject to a substantial redistribution in the ZnSe layer, which is affected by the growth conditions and the presence of an annealing step. These results show that it is possible to fabricate a sharp interface between a magnetic semiconductor (Zn(Mn)Se) and high quality GaAs, with low dopant concentration and good optical properties.

Influence of Analysis Parameters on the Microstructural Characterization of Nanoscale Precipitates

2009 ◽  
Vol 1231 ◽  
Author(s):  
Ai Serizawa ◽  
Michael K. Miller
Keyword(s):  
Microstructural Characterization ◽  
Atom Probe ◽  
Separation Method ◽  
Nanometer Scale ◽  
Analysis Method ◽  
Voxel Size ◽  
Interface Width ◽  
Optimum Analysis ◽  
Maximum Separation

AbstractA series of simulated microstructures containing nanometer-scale precipitates was created with an atom probe simulator. These data were then analyzed with the proximity histogram and the maximum separation method to determine the influence of the particular analysis method. For simulated 2-nm-radius spherical precipitates, the optimized voxel size and delocalization were found to be 0.5-0.6 nm and 1.0-1.5 nm, respectively. Under optimum analysis parameters, the voxelization/delocalization process only slightly degrades the interface width determined from the proximity histogram to ˜0.15±0.04 nm.

Growth of GaN without Yellow Luminescence

1995 ◽  
Vol 395 ◽  
Author(s):  
X. Zhang ◽  
P. Kung ◽  
D. Walker ◽  
A. Saxler ◽  
M. Razeghi
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Native Defect ◽  
Yellow Luminescence ◽  
Gallium Vacancy ◽  
Rich Condition

ABSTRACTWe report the growth and photoluminescence characterization of GaN grown on different substrates and under different growth conditions using metalorganic chemical vapor deposition. The deep-level yellow luminescence centered at around 2.2eV is attributed to native defect, most possibly the gallium vacancy. The yellow luminescence can be substantially reduced By growing GaN under Ga-rich condition or doping GaN with Ge or Mg.

Preparation and characterization of epitaxial iron oxide films

1998 ◽  
Vol 13 (7) ◽  
pp. 2003-2014 ◽  
Author(s):  
Y. Gao ◽  
Y. J. Kim ◽  
S. A. Chambers
Keyword(s):  
Growth Rate ◽  
Iron Oxide ◽  
Oxygen Plasma ◽  
Film Surface ◽  
Surface Region ◽  
Growth Conditions ◽  
Epitaxial Films ◽  
Pure Phase ◽  
Iron Oxide Films

Well-ordered, pure-phase epitaxial films of FeO, Fe3O4, and γ–Fe2O3 were prepared on MgO(001) by oxygen-plasma-assisted MBE. The stoichiometries of these thin films were controlled by varying the growth rate and oxygen partial pressure. Selective growth of γ–Fe2O3 and α–Fe2O3 was achieved by controlling the growth conditions in conjunction with the choice of appropriate substrates. Growth of the iron oxide epitaxial films on MgO at ≥350 °C is accompanied by significant Mg outdiffusion. The FeO(001) film surface exhibits a (2 × 2) reconstruction, which is accompanied by a significant amount of Fe3+ in the surface region. Fe3O4 (001) has been found to reconstruct to a structure. γ–Fe23 (001) film surface is unreconstructed.

Atom probe crystallography: Characterization of grain boundary orientation relationships in nanocrystalline aluminium

2011 ◽  
Vol 111 (6) ◽  
pp. 493-499 ◽  
Author(s):  
Michael P. Moody ◽  
Fengzai Tang ◽  
Baptiste Gault ◽  
Simon P. Ringer ◽  
Julie M. Cairney
Keyword(s):  
Grain Boundary ◽  
Atom Probe ◽  
Orientation Relationships ◽  
Boundary Orientation

scholarly journals Atom Probe Tomography Characterization of Engineered Oxide Multilayered Structures

2015 ◽  
Vol 21 (S3) ◽  
pp. 845-846
Author(s):  
M. I. Nandasiri ◽  
N. Madaan ◽  
A. Devaraj ◽  
J. Bao ◽  
Z. Xu ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Atom Probe ◽  
Multilayered Structures

scholarly journals Characterization of the Antibiotic Compound No. 70 Produced byStreptomycessp. IMV-70

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Lyudmila P. Trenozhnikova ◽  
Almagul K. Khasenova ◽  
Assya S. Balgimbaeva ◽  
Galina B. Fedorova ◽  
Genrikh S. Katrukha ◽  
...  
Keyword(s):  
Optimal Growth ◽  
Growth Conditions ◽  
Culture Broth ◽  
Producer Strain ◽  
New Class ◽  
New Antibiotics ◽  
Actinomycete Strain ◽  
Main Component

We describe the actinomycete strain IMV-70 isolated from the soils of Kazakhstan, which produces potent antibiotics with high levels of antibacterial activity. After the research of its morphological, chemotaxonomic, and cultural characteristics, the strain with potential to be developed further as a novel class of antibiotics with chemotherapeutics potential was identified asStreptomycessp. IMV-70. In the process of fermentation, the strainStreptomycesspp. IMV-70 produces the antibiotic no. 70, which was isolated from the culture broth by extraction with organic solvents. Antibiotic compound no. 70 was purified and separated into individual components by HPLC, TLC, and column chromatography methods. The main component of the compound is the antibiotic 70-A, which was found to be identical to the peptolide etamycin A. Two other antibiotics 70-B and 70-C have never been described and therefore are new antibiotics. The physical-chemical and biological characteristics of these preparations were described and further researched. Determination of the optimal growth conditions to cultivate actinomycete-producer strain IMV-70 and development of methods to isolate, purify, and accumulate preparations of the new antibiotic no. 70 enable us to research further the potential of this new class of antibiotics.

Sign in / Sign up

Export Citation Format

Share Document