IJS KOLOKVIJ, četrtek, 22. 11. 2018, ob 10. uri, prof. dr. Rafal E. Dunin-Borkowski

[Natasa Gosevac]

Vabimo vas na 2. predavanje iz sklopa "Kolokviji na IJS" v letu 2018/19, ki
bo v četrtek, 22. novembra 2018, ob 10. uri v Veliki predavalnici Instituta
>Jožef Stefan<  na Jamovi cesti 39 v Ljubljani. Napovednik predavanja
najdete tudi na naslovu  <http://www.ijs.si/ijsw/Koledar_prireditev>
http://www.ijs.si/ijsw/Koledar_prireditev, posnetke preteklih predavanj pa
na  <http://videolectures.net/kolokviji_ijs>
http://videolectures.net/kolokviji_ijs. 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



prof. dr. Rafal E. Dunin-Borkowski

Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons,
Forschungszentrum Jülich, Nemčija

 

Merjenje elektromagnetnega polja z nanometrsko ločljivostjo s presevnim
elektronskim mikroskopom

 

V preteklih letih smo doživeli preporod presevne elektronske mikroskopije,
do katerega je prišlo tako zaradi vpeljave nove strojne opreme, kot so
izvori elektronov na poljsko emisijo, korektorji aberacij ter nosilci za
in-situ eksperimente, kot tudi zaradi razvoja novih tehnik, algoritmov in
programske opreme, ki izkoriščajo večjo hitrost računalnikov ter zmožnost
nadzora in avtomatizacije sodobnih elektronskih mikroskopov. Ta razvoj je
omogočil neposredno snemanje strukture materialov s prostorsko ločljivostjo,
manjšo od 50 pm. V predavanju bom opisal, kako lahko s presevno elektronsko
mikroskopijo pridobimo poleg kvantitativne informacije o lokalni
mikrostrukturi in kemiji sestavi materialov tudi podatke o magnetnem polju
in porazdelitvi gostote naboja z domala atomsko ločljivostjo. Če te podatke
združimo z iterativno rekonstruiranimi modeli, elektronsko tomografijo in z
in-situ rezultati, lahko dobimo kvantitativno informacijo o magnetnih
lastnosti materiala in sicer v treh razsežnostih, to je v odvisnosti od
temperature, zunanjega polja ter reaktivnih plinov. V predavanju bodo
predstavljeni rezultati, ki se nanašajo na preiskave  posameznih magnetnih
nanokristalov in skirmionov v razširjenih plasteh in v geometrijsko omejenih
strukturah. Predavanje bom sklenil z osebnim pogledom na smeri razvoja
presevne elektronske mikroskopije, ki utegnejo zahtevati korenite spremembe
zasnove mikroskopov, dolgotrajnejše eksperimente, kvantitativno primerjavo
rezultatov meritev s komplementarnimi tehnikami in naprednimi simulacijami
ter nove pristope pri obdelavi in shranjevanju podatkov.

Predavanje bo v angleščini.

Lepo vabljeni!

*****

 




We invite you to the 2nd Institute colloquium in the academic year 2018/19.
The colloquium will be held on Thursday November 22, 2018 at 10 AM in the
main Institute lecture hall, Jamova 39, Ljubljana. To read the abstract
click   <http://www.ijs.si/ijsw/Koledar_prireditev>
http://www.ijs.si/ijsw/Koledar_prireditev. Past colloquia are posted on
<http://videolectures.net/kolokviji_ijs>
http://videolectures.net/kolokviji_ijs.

 

********************************************

prof. dr. Rafal E. Dunin-Borkowski

Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons,
Forschungszentrum Jülich, Germany

 

Electromagnetic field mapping at the nanoscale in the transmission electron
microscope

 

Transmission electron microscopy has been revolutionized in recent years,
both by the introduction of new hardware such as field-emission electron
guns, aberration correctors and in situ stages and by the development of new
techniques, algorithms and software that take advantage of increased
computational speed and the ability to control and automate modern electron
microscopes. These developments have resulted in the ability to provide
direct images of the internal structures of materials with a spatial
resolution of better than 50 pm. In this talk, I will describe how electron
microscopy can be used to obtain quantitative information about not only
local microstructure and chemistry in materials but also magnetic fields and
charge density distributions with close-to-atomic spatial resolution. When
combined with model-based iterative reconstruction, electron tomography and
in situ techniques, this information can be obtained quantitatively, in
three dimensions, as a function of temperature and in the presence of
applied fields and reactive gases. I will present results obtained from
materials that include individual magnetic nanocrystals and skyrmions in
extended films and geometrically confined structures. I will conclude with a
personal perspective on directions for the future development of
transmission electron microscopy, which may require radical changes to the
design of electron microscopes, longer experiments, quantitative comparisons
of experimental measurements with both complementary techniques and advanced
simulations, and new approaches for data handling and storage.

 

Cordially invited!

 

 

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