A one-day international school, coordinated by Vladimir Skuratov (JINR, Russia), will take place before the REI-20 conference on August 18, 2019.

This REI-20 International School is principally dedicated to young researchers (PhD students, post-docs, junior assistant researchers…). The program of School will consist of lectures on defect formation mechanisms, basic properties of radiation defects and structural characterization of radiation damage in insulating and non-metallic materials using optical spectroscopy, ion beam analysis and transmission electron microscopy.

Sunday, August 18, 2019


TIME

EVENT

PLACE

09:15 - 09:45

Registration

Main building ENU, ground floor

09:50 - 10:00

Opening ceremony

Vladimir Skuratov

 

10:00 - 11:15

Introduction to ion beam analysis

Prof. Marko Karlušić

 

 

11:15 - 11:30

Coffee break

 

11:30 - 12:45

Review of Radiation Damage and Basic Properties of Point Defects in Wide-Band Gap Metal Halides, Oxides and Perovskites

Dr. Anatolii Popov

 

12:30 - 14:00

Launch

 

14:00 - 15:15

Creation mechanisms of structural defects in insulators under different type/density of irradiation

Prof. Aleksandr Lushchik

 

 

15:15 - 15:30

Coffee break

 

15:30 - 16:45

TEM as a tool for studying material modification at the atomic scale

Dr. Jacques O'Connell

 


Brief information

Introduction to ion beam analysis

Dr. Marko Karlušić
Ruđer Bošković Institute,
Zagreb, Croatia

General overview of the available ion beam analysis (IBA) techniques will be given. Special attention will be paid to IBA techniques that can be used to study material modifications due to ion irradiation. Finally, examples of in situ IBA relevant for ion track research will be presented.



Review of Radiation Damage and Basic Properties of Point Defects in
Wide-Band Gap Metal Halides, Oxides and Perovskites

Dr. Anatoli I. Popov
Institute of Solid State Physics, University of Latvia,
Riga, Latvia

I will present an update survey of the optical properties of primary radiation-induced point defects in alkali halides, binary oxides and also some oxide and halide perovskites.  We will discuss in details the optical properties of single electron F and F+ centers in rock-salt (fcc) alkali halides and oxides and show how that the Mollwo-Ivey law, well-known for the F-type centers in alkali halides, may be extended for other rock-salt insulators. We will also discuss the major differences in point defect production mechanisms in halides and oxides. We will see how the Rabin-Klick diagram may be generalized for a whole family of alkali halides. We will discuss also the correlation between the temperatures at which hole polarons start migration in a series of alkali halides (fluorites, chlorides, bromides, iodides) and the appropriate lattice parameters. Finally, the F-type center migration and aggregation into metal colloids in alkali halides and oxides will be also discussed. Special attention will be paid to a detailed comparison of diffusion-controlled F center thermal annealing in neutron, electron and heavy-ion irradiated materials.


Creation mechanisms of structural defects in insulators under different type/density of irradiation

Prof. Aleksandr Lushchik
Institute of Physics, University of Tartu
Tartu, Estonia

Besides universal knock-on mechanism of defect creation that is dominant in metals and semiconductors, several ionization mechanisms of radiation damage should be considered in wide-gap materials as well. There are there competitive dissipation channels for the energy of electronic excitations (EEs) resulting in luminescence, heat release (phonon package) and creation of point defects. Different types of luminescence as well as their dependence on temperature and excitation density will be discussed. The criteria for the efficient decay of EEs into Frenkel defects as well as specificity of defect creation under conditions of high density of EEs will be presented. Besides extremely high EE density within swift heavy ion tracks, a high local density of EEs can be also realized under VUV/synchrotron radiation, when an exciting photon simultaneously forms a group (2-6) of EEs (i.e. the process of EE multiplication), which can be efficiently transformed into a group of spatially close point defects.


TEM as a tool for studying material modification at the atomic scale

Dr. Jacques O'Connell
Centre for HRTEM, Nelson Mandela University,
Port Elizabeth, South Africa

When studying structural alterations at nanometric scale, few techniques can compete with transmission electron microscopy in terms of absolute spatial resolution. The ability to directly image atomic columns with simultaneous chemical information at sub-angstrom resolution makes TEM especially useful in the study of SHI induced tracks/defects in crystals. The presentation will start with a little history of the development of the TEM and the reasons therefore. A brief introduction to basic crystallography and the concept of diffraction by a crystal lattice will then lead to the basic construction of a microscope in order to take advantage of this effect. A discussion on varying modes of operation including but not limited to conventional TEM, HRTEM, diffraction and scanning mode imaging will serve to demonstrate the versatility of the instrument as a pure imaging device. Various secondary signals such as x-rays and inelastically scattered electrons are also produced. These signals are exploited in EDS, EELS and EFTEM in order to gain chemical understanding of studied materials. Finally, some real-world examples will be demonstrated together with a discussion of experimental optimization and specimen preparation.