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Centre of
Photon, Electron and Ion Advanced Methods for Natural Science |
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International Mini-Workshop on |
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April 19-23, 2004 Institute of Physics Polish Academy of Science Warsaw, Poland The Quantitative High Resolution
Transmission Electron Microscopy
(QHRTEM) starts to play an
important role in characterization of such semiconductor
nanostructures as QDs, QW and QWR. However, the complex workflow is necessary
to achieve the optimal artifact free results of local strains and chemical
mapping with near atomic resolution by image processing of the HRTEM images.
In the case of studying a nanosegregation process and an interface
characterization in ternary systems this method surpasses all analytical
methods, from the resolution and sensitiveness point of view. The staff of
the Centre of Excellence CEPHEUS
have a share in their experience
in this domain (know-how) organizing the highly focused workshops dedicated to young researchers. The optimization of the QHRTEM
experiment, adequate image processing using the Peek Finding (PF) as well
the Geometric Phase (GP) methods
was the subject of detailed presentation and practical exercises at the
workshop organized in Warsaw in
April 2004. During 5 days’ workshops the young
researchers from Poland, Greece, Spain and France have had the possibility
for practical application of these methods, on their own images, from current
researches. During training sessions the participants have
also had opportunity to digitize and to process the negatives in
optimal conditions due to high
quality scanners, computers and networking infrastructure. The experimental
remote computing technique (created for the workshop) has been used to permit
all participants to make images processing separately on the central server.
This successful informatics experiment gives the potential technical
possibilities for organization of the virtual training courses in the future.
The second theoretical part of the workshop has been devoted to the presentation of the Finite Element and Molecular Dynamic computation methods and to the topological description of defects. The lectures were performed by the invited specialists and were focused on the practical application of advanced computation for quantitative interpretation of the HRTEM images, especially taking into account the relaxation of the stress in thin TEM samples. The special lectures were reserved for young researchers who had opportunity to present and discuss the problems met during their researches and which they hoped to solve using the QHRTEM images. PROGRAM of Mini-Workshop
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19 April |
Monday |
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14:00-16:00 |
Registration |
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16:00-18:00 |
Setting
users’ computers privileges (connection to network and configuration of
laptop, user account creation on application servers etc.) |
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18:00 |
Social
event |
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20 April |
Tuesday |
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9:15 |
Workshop
targets – QHRTEM overview S. Kret, Institute of Physics, PAS, Warsaw, Poland |
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10:00 |
HRTEM
image processing for strain measurement by the peak finding method. |
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10:45 |
Coffee
break |
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11:00 |
Noise
reduction in Fourier and/or real space and their artifacts - On‑line
demonstration P. Dłużewski, Institute of Physics, PAS Warsaw,Poland |
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12:30 |
Lunch
break |
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14:00-18:00 |
Training:
Peak finding procedure and strain measurement. |
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21
April |
Wednesday |
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9:00-12:30 |
Training: Impact of noise
reductions on the measured distortions |
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12:30 |
Lunch break |
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13:45 |
Introduction
to Geometric Phase Methods of strain measurement. Tutorial
lecture with on‑line processing demonstration S. Kret, Institute of Physics, PAS Warsaw,Poland |
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14:30 |
Determination of artificial image
distortion in Super STEM images A. Sanchez, University of Liverpool,UK |
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15:30 |
Integrated methodology for the microstructural and energetical
characterization of interfacial defects: topological analysis G.P. Dimitrakopulos,
University of Thesaloniki, Greece |
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16:30 |
Coffee break |
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16:45 |
Growth temperature effect on the
phase separation of InGaAsN QWs
M. Herrera., Department of Materials Science
and Metallurgical Engineering and Inorganic Chemistry. University of Cadiz,
Spain |
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17:10 |
S. Protima, T. Wojtowicz , and
P.Ruterana SIFCOM, Caen, France |
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17:35 |
CdTe/ZnTe and Si/Ge QDs
M. Żak,
Institute of Physics, PAS Warsaw,Poland |
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18:00 |
Chemical Composition determination
of InAs/InP (001) quantum wires and InAs/GaAs (001) quantum rings stacked structures from
HRTEM images. T. Ben Fernández,
Department of
Materials Science and Metallurgical Engineering and Inorganic Chemistry.
University of Cadiz, Spain |
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22
April |
Thursday |
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9:00-12:30 |
Training: Geometric Phase and
individual participant subject choice |
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12:30 |
Lunch break |
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14:00 |
Foundations of Finite Element Method and their
application to analysis of heterostructures -
Tutorial and demonstration on examples. G. Maciejewski,
Institute of Fundamental Technological Research PAS, Warsaw, Poland |
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15:00 |
From strain to stress state and chemical composition
- Tutorial and demonstration on examples. G. Jurczak, IPPT,
Institute of Fundamental Technological Research PAS, Warsaw, Poland |
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16:00 |
Round Table:
- Advantage, difficulties and limitations in image processing of HRTEM
- QHRTEM as standard characterization method? |
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19:00 |
Barbecue in open air (if
the weather is fine ) |
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23
April |
Friday
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9:30 |
Image simulation with large super cell as ultimate
approach in quantitative interpretation of images P. Dłużewski,
Institute of Physics, PAS Warsaw |
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10:15 |
Molecular static’s empirical
potential in super-cell calculations for HRTEM simulation - Tutorial and
examples. P. Traczykowski,
Institute of Fundamental Technological Research PAS, Warsaw, Warsaw |
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11:00 |
Integrated methodology for the microstructural and energetical
characterization of interfacial defects - Large scale energetic calculations J. Kioseoglou,
University of Thesaloniki, Greece |
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11:45 |
Molecular Dynamics primer for nano-modeling Z. Kaszkur,
Institute
of Physical Chemistry, PAS, Warsaw, Poland |
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12:30 |
Lunch break |
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14:00-17:00 |
Training: Individual
participants subject choice. |
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17:00 |
Workshop closing remarks |
It would be useful to bring a laptop PC if possible.
Slawomir Kret,
Institute of Physics,
PAS Warsaw,Poland, kret@ifpan.edu.pl
Piotr Dluzewski
Institute of Physics, PAS Warsaw,Poland
dluzew@ifpan.edu.pl
Ana Sanchez, University of
Liverpool, a.sanchez-fuentes@liverpool.ac.uk