Knut W. Urban, Ultra-High Resolution Study by Aberration-Corrected TEM of Pyrochlore BZN Supplying Information on Displacive Atom-Site Disorder
YUCOMAT 2021
Herceg Novi, Montenegro, 2021
YUCOMAT 2021
Openning
YUCOMAT 2021
Competition : : Best Poster Presentation
YUCOMAT 2021
Competition : : Best Poster Presentation
YUCOMAT 2021
MRS Serbia
YUCOMAT 2021
Competition : : Best Poster Presentation
YUCOMAT 2021
Yury Gogotsi - Award for a Lasting and Outstanding Contribution to Materials Science and Engineering
YUCOMAT 2021
Herceg Novi, Montenegro, 2021
YUCOMAT 2021
In Between
YUCOMAT 2021
Awards & Closing
YUCOMAT 2021
Herceg Novi, Montenegro, 2021
YUCOMAT 2021
Audience
YUCOMAT 2021
Discussion
YUCOMAT 2021
In Between
YUCOMAT 2021
Poster Session
YUCOMAT 2021
Audience
YUCOMAT 2021
Discussion
YUCOMAT 2021
Audience - outside
YUCOMAT 2021
MRS Serbia
YUCOMAT 2021
Discussion
YUCOMAT 2021
Herceg Novi, Montenegro
YUCOMAT 2021
In Between
YUCOMAT 2021
MRS Serbia
YUCOMAT 2021
Herceg Novi, Montenegro
YUCOMAT 2021
MRS Serbia
YUCOMAT 2021
Audience
YUCOMAT 2021
Herceg Novi, Montenegro

Knut W. Urban (1,2), Chun-Lin Jia (1,2) and Hong Wang (2)

(1) PGI-5 and Ernst Ruska Center, Research Center Juelich, Juelich/Germany.
(2) School of Electronic and Information Engineering and State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an/China.

Pyrochlores, chemical formula A2B2O7, form an extended class of materials with interesting properties. The compound Bi1.5ZnNb1.5O7 (BZN) is prototypical. Its excellent dielectric properties make it attractive, e.g. for capacitors, tunable microwave devices and electric-energy storage equipment. Investigating BZN we report on the first study on a pyrochlore by atomic-resolution transmission electron microscopy. In this study – at the forefront of what modern electron microscopy can do – we are able to realize picometer-precision in our images of the close atom pairs with a separation of only 20 pm. We find that the position of the atomic intensity maxima do not coincide with the projected Wyckoff positions of the basic pyrochlore lattice. This supplies atomic-scale evidence for displacive disorder on split (cage-like) A-type sites. From our studies on atom mobility during microscopic observation we can conclude that it is the Zn-atom jumps and not those of Bi or Nb that are responsible for dielectric relaxation.

Plenary lectures - YUCOMAT 2018

member since 2008