wird auf einen späteren Termin verschoben
Dr. Y.C Wu, Universität Stuttgart, Institut für Theoretische und Angewandte PhysikStructural evolution of nanocrystalline Pr2Fe14B and Nd2Fe14B hard magnets studied by positron spectroscopy techniques
Do. 16. Mai 2002
Dr. K. Sato, Universität Stuttgart, Institut für Theoretische und Angewandte PhysikStudy of quasicrystals by positron annihilation
Do. 23. Mai 2002
Dr. K. Reimann, Universität Stuttgart, Institut für Theoretische und Angewandte PhysikZr segregation in nanocrystalline Pd-Zr and Fe-diffusion in the Nd-rich intergranular phase of fine-grained Fe14Nd2B
Do. 6. Juni 2002
G. Knöner, Universität Stuttgart, Institut für Theoretische und Angewandte PhysikSauerstoffdiffusion in nanokristallinem ZrO2 x Y2O3
Do. 13. Juni 2002
Dr. R.-W. Röwer, Universität Stuttgart, Institut für Theoretische und Angewandte PhysikSauerstoffdiffusion in Pyrolysekeramiken
Do. 20. Juni 2002
K.J. Reichle, Universität Stuttgart, Institut für Theoretische und Angewandte PhysikStrahlenschutzbelehrung
Do. 27. Juni 2002
Dr. F. Jelezko, Universität Stuttgart, 3. Physikalisches InstitutQuantum computation with single defect centers
Wintersemester 2001/2002
Mo. 29. Oktober 2001,
11:30 Uhr
Diffusion and related phenomena in polycrystalline and
nanostructured metals and nanocomposites
Do. 18. Oktober 2001
Nanostructured Metastable Alloys Processed by Severe Plastic Deformation
Do. 19. April 2001
Das Ausheilen der Siliziumluecke in
bestrahltem 6H-SiC
Do. 26. April 2001
Atomare chemische Umgebung in Festkoerpern und Positronen
Dopplerverbreiterungsspektroskopie
Do. 3. Mai 2001
Polarization Microscopy with hard X-rays
Do. 10. Mai 2001
Gitterparametermessungen an 6H-SiC mittels Roentgenbeugung
Do. 17. Mai 2001
Deep Level Transient Spectroscopy an Siliziumkarbid -
Grundlagen und Ergebnisse
Do. 31. Mai 2001
Microstructure of transition metals assembled into mesoporous silica
Do. 7. Juni 2001
Strahlenschutzbelehrung
Do. 21. Juni 2001
Fe-diffusion in grain-boundaries of nanocrystalline Fe14Nd2B
Do. 19. Juli 2001
Multifunktionalität durch Nanostrukturmaterial
Do. 2. August 2001
Atomic defects in semiconductors studied by one-dimensional angular
correlation of annihilation radiation technique
Mo. 10. September 2001,
(Zeit: 15:30 Uhr)
Positron Annihilation Sudies on High-Tc Superconductors
Shape-parameter,S, determined from Doppler Broadening of Positron Annihilation Radiation Lineshape measurement, gives the fraction of suitably defined low momentum electrons among the annihilating electrons. Since BCS pairing in momentum space is accepted for the so-called conventional superconductors, such studies of possible changes in electron momentum distribution due to superconducting transition in high temperature superconductors should help clarify the yet unknown mechanism of superconducting pairing in HTSC. Our S vs. T data at close interval (down to 1 K) of temperature reveal two minima (at Tc and 0.95 Tc) in (Bi,Pb)-2223 pellets and Y-123 single crystals and one minimum at Tc in Bi-2212, in addition to the somewhat better known step-like change at Tc. These new observations imply a peculiar re-distribution of electron momentum as a result of superconducting transition.
Do. 13. September 2001
Grain boundary state of nanocrystalline Au prepared by gas deposition method
High-density nanocrystalline (n-) Au specimens have been prepared by means of the gas deposition method, where ultrafine Au particles formed by the inert-gas condensation are directly transferred onto a substrate in a few ms. Two types of the specimens with different properties have been prepared by controlling the deposition rate (DR) of the ultrafine Au particles. The type-H specimens prepared at the DR beyond 800 nm/s show Young’s modulus of 78 GPa at 10 K and start the grain growth below 400 K, in contrast, the type-L specimens at the DR below 800 nm/s show Young’s modulus of 83 GPa at 10 K and start the grain growth above 400 K. From the boundary DR of 800 nm/s, the relaxation time of about 0.016 s is estimated for a certain rearrangement of the ultrafine Au particles on the specimen surface, which would be responsible for branching off of the specimen types. The grain boundary state of the type-L and -H specimens will be mentioned.
Do. 14. Dezember 2000
Ordnungsverhalten von Stickstoff in
binaeren Nitriden einiger 3d-Metalle Do. 23. November 2000
K.
Reimann, Institut fuer Theoretische und Angewandte Physik
F. Baier, Institut fuer Theoretische und Angewandte Physik
Vacancies in AlPdMn: An approach by positron annihilation spectroscopy
Do. 9. November 2000
K. Blaurock, Institut fuer Theoretische und Angewandte Physik
Untersuchung der Elektronenimpulsverteilung in Festkoerpern mit Positronen
Do. 19. Oktober 2000
Belehrung nach der Strahlenschutzverordnung Atomic ordering and phase
equilibria in strongly nonstoichiometric carbides and nitrides
Experimental and theoretical
data on order-disorder phase transformations in strongly nonstoichiometric
carbides and nitrides of Group IV and V transition metals are reviewed.
Application of the Order Parameter Functional Method to atomic and vacancy
ordering in nonstoichiometric compounds and to phase equilibria calculations
for M-X (X = C, N) systems is discussed. Effect of ordering on some properties
of nonstoichiometric carbides is considered
Do. 11. Mai 2000
Preparation of nanocrystalline
materials under high pressure HREM investigations of
nanocrystalline FeZrB and PdZr alloys. EU-Projekte managen: Zusammenfassung
eines Fortbildungsseminars der Universität Stuttgart Investigation of the
ternary Al-Pd-Co system Atomic defects in
ternary B2-(Fe,Ni)Al alloys studied by time-differential dilatometry Nanokristalline Materialien
mit durchstimmbaren elektronischen EigenschaftenDr. Y. Kolobov,
Inst. Strength Physics and Materials Science, Russian Academy
of Sciences, Tomsk, Russia
Dr. Y.Y. Stolyarov,
Inst. Physics of Adv. Mater., Ufa State Aviation Technical University, Ufa, Russia
By now it is well established that severe plastic deformation (SPD) has an ability in either strongly refine microstructure till up nanometer range and change essentially a phase composition forming highly metastable states in bulk samples of various alloys. Therefore, there is a potential to achieve a new and extraordinary properties. However, attaining such properties is complex problem, which depends on different processing and microstructural parameters. The report focuses on SPD processing by high pressure torsion and equal channel angular pressing of several Ti, Al and hard magnetic Pr2Fe14B based alloys. It is shown that for microstructures of SPD materials it is typical to have a presence of not only small grain size, but also specific defect structures, high internal stresses, and often a formation of supersaturated solid solutions and amorphyzation of intermetallic phases in these alloys. During further heating ageing effects and reordering take place and processed alloys demonstrate unique mechanical (strength and superplasticity) and magnetic properties.
Sommersemester 2001
Thomas Lingner,
Universitaet Paderborn, Fachbereich Physik
Kay Blaurock,
Universitaet Stuttgart, Institut fuer Theoretische und Angewandte Physik
Dr. K. Sato,
Tokyo University, Department of Applied Physics
Christoph Seitz,
Universitaet Erlangen, Lehrstuhl fuer Kristallographie und
Strukturphysik
M. Krieger,
Universitaet Erlangen, Lehrstuhl fuer Angewandte Physik
Dr. Y. Wu,
Hefei University of Technology, Faculty of Matererials Science and Engineering
N.N.,
Dr. F. Ye,
Institut für Nanotechnologie, Forschungszentrum Karlsruhe
Dipl. Ing. F. Kauffmann,
Max-Planck Institut fuer Metallforschung, Stuttgart, Seestr.
Dr. N.Y. Arutyunov,
Arifov Institute of Electronics, Tashkent, Uzbekistan
Dr. D. Sanyal,
Department of Physics, University of Calcutta, India
Dr. H. Tanimoto,
Institute of Materials Science, University of Tsukuba, Tsukuba, Japan
Wintersemester 2000/2001
Dr. A. Leineweber,
Max-Planck-Institut fuer Metallforschung, Stuttgart, Seestr. 92
Atomistische Modellierung der
Ordnungseinstellung in den nanokristallinen intermetallischen Verbindungen
FeAl, NiAl und Fe3Si
Do. 16. November 2000
A. Strohm, Institut fuer Theoretische und Angewandte Physik
Belehrung ueber den Umgang mit
radioaktiven Stoffen. Die Teilnahme ist gemaess Paragraph 39 der
Strahlenschutzverordnung fuer alle diejenigen, die mit radioaktiven Stoffen
umgehen, bzw. dieses planen, verbindlich.
Do. 5. Oktober 2000
(Zeit: 13:30 Uhr)
Prof. A.I. Gusev, Institute of Solid State Chemistry, Russian Academy of Sciences, Ekaterinburg, Russia
Mo. 25. September 2000
(11:00 Uhr)
Albina Valeeva, Institute
of Solid State Chemistry, Russian Academy of Sciences, Ekaterinburg, Russia
The structure and properties
of cubic titanium monoxide TiOy with vacancies on both titanium and oxygen
sublattices.
Sommersemester 2000
Dr. X.Y. Zhang, Institute
of Physics, Chinese Academy of Sciences, Beijing, China
Do. 18. Mai 2000Prof. G. Tang, Dept.
of Mater. Sci and Eng., Tsinghua University, Beijing China
Do. 25. Mai 2000
K. Reimann, ITAP
Fr. 16. Juni 2000 (Zeit:
14:00
Uhr, Ort: ITAP
Bibliothek 6-141)
M. Yurechko, Inst. f. Festkörperforschung, Forschungszentrum Jülich
Do. 13. Juli 2000
W. Sprengel, ITAP
Di. 25. Juli 2000
PD Dr. R. Würschum,
Inst. f. Nanotechnologie, Forschungszentrum Karlsruhe
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