«ANNUAL REPORT Riga 2012 Annual Report 2011, Institute of Solid State Physics, University of Latvia. Editor: A.Krumins. Composed matter: A.Muratova. ...»
Institute of Solid State Physics
University of Latvia
Annual Report 2011, Institute of Solid State Physics, University of Latvia.
Editor: A.Krumins. Composed matter: A.Muratova. Set up at the Institute of Solid State
Physics, University of Latvia, Kengaraga Str.8, Riga LV – 1063, Latvia.
Riga, Institute of Solid State Physics, University of Latvia, 2012, p.159
Director: Dr. habil. phys. A.Sternberg
Institute of Solid State Physics, University of Latvia 8 Kengaraga Str., LV-1063 Riga Latvia Tel.: +371 67187816 Fax: +371 67132778 http://www.cfi.lu.lv © Institute of Solid State Physics, University of Latvia
CONTENTSIntroduction 4 Department of Crystal Physics 9 Department of Disordered Material Physics 17 Department of Ferroelectrics Physics 27 Department of Semiconductor Materials 57 Laboratory of Theoretical Physics and Computer Modelling 80 Laboratory of Optical Recording 104 Laboratory of Visual Perception 111 Laboratory of Wide Band Gap Materials 113 Laboratory of Surface Physics 117 Department of Radiation Physics 122 Laboratory of Organic Materials 133 Laboratory of Electronic Engineering 142 Appendix 144
INTRODUCTIONThe research in solid state physics at the University of Latvia restarted after World War II.
The Institute of Solid State Physics (ISSP) of the University of Latvia was established on the basis of Laboratory of Semiconductor Research and Laboratory of Ferro- and Piezoelectric Research in 1978. Since 1986 the ISSP has the status of an independent organization of the University and now is the main material science institute in Latvia.
Four laboratories from the Institute of Physics of the Latvian Academy of Sciences joined our Institute in 1995. Twenty scientists of the former Nuclear Research Centre joined the ISSP in 1999 and established Laboratory of Radiation Physics. In 2004 scientists from the Institute of Physical Energetics joined ISSP and established Laboratory of Organic Materials (Table 1).
In mid 90-ties the ISSP has intensified its teaching activities. A number of researcher have been elected as professors of the University of Latvia. Post-graduate and graduate curricula were offered in solid state physics, material physics, chemical physics, physics of condensed matter, semiconductor physics, and experimental methods and instruments. In 2002 the Chair of Solid State and Material Physics University of Latvia was established at ISSP.
Research and training in optometry and vision science is taking place in the Laboratory of Visual Perception of the ISSP since 1992. Co-located with the Institute, the Optometry Centre has been established in 1995 with facilities for primary eye care and serving as a technological research basis for students and staff.
In December 2000 the ISSP was awarded the Centre of Excellence of the European Commission (Centre of Excellence for Advanced Material Research and Technologies). This honorary recognition with the accompanying financial support of 0,7 million EUR has increased our research activities, particularly extending the list of our research partners and scientists who come to work to our Institute from the leading European research centres.
The research of the ISSP includes:
• electron and ion process in wide-gap materials with different degree of ordering;
• functional organic molecules and polymers for photonics and organic electronics;
• multifunctional and hybrid materials for energy applications: light emitting diodes, photovoltaic elements and coatings for solar baterries, storage of hydrogen for fuel cell devices;
• electrodes and plasma technologies for hydrogen production, polymer membranes with ionic conduction for fuel cells and gas separations;
• inorganic single crystals, ceramics, glasses, thin films, and nano-structured surfaces for application in optics, electronics, photonics and energetics.
The highest decision-making body of the Institute is the Scientific Council of 21 members elected by the employees of the Institute (Table 2). Presently Dr. phys. L.Trinklere is the elected chairperson of the ISSP Council. The Council appoints director and its deputies.
The International Supervisory Board of ISSP was established in 1999 and it consists now of 11 members (Table 3). The first International evaluation of ISSP was perfomed in
2002. The second Meeting of International Supervisory board took place at April 3, 2007.
Below is a short excerpt citation from the evaluation report: “… the overall development of ISSP has been good with excellent quality of research as evidenced by publications, active participation in international projects etc…” The interdisciplinary approach of research at the ISSP is reflected by its highly qualified staff. At present there are 176 employees working at the Institute, 26 of 103 members of the research staff hold Dr.habil.degrees, 66 hold Dr. or PhD. At the end of 2011 there were 21 PhD students and 46 undergraduate and graduate students in physics and optometry programmes working at the ISSP.
The Scientific Council of the Institute
1. Laima Trinklere, Dr.phys., chairperson of the Council
2. Marcis Auzins, Dr.habil.phys.
3. Larisa Grigorjeva, Dr.habil.phys.
4. Jurģis Grūbe, PhD student
5. Anastasija Jozepa
6. Andris Krumins, Prof., Dr.habil.phys.
7. Peteris Kulis, Dr.phys.
8. Aleksejs Kuzmins, Dr.phys.
9. Kaiva Lūse, PhD student
10. Inta Muzikante, Dr.habil.phys.
11. Juris Purāns, Dr.phys.
12. Uldis Rogulis, Dr.habil.phys.
13. Mārtins Rutkis, Dr.phys.
14. Andrejs Silins, Prof., Dr.habil.phys.
15. Linards Skuja, Dr.habil.phys.
16. Anatolijs Sharakovskis, PhD student
17. Andris Sternbergs, Dr.habil.phys.
18. Janis Teteris, Dr.phys.
19. Anatolijs Truhins, Dr.habil.phys.
20. Nils Veidemanis, A/S “Sidrabe”
21. Guntars Zvejnieks, Dr.phys.
Table 3 International Advisory Board of the Institute
1. Prof. Dr.J.Banys, University of Vilnius, Lithuania
2. Prof. Dr. Gunnar Borstel, University of Osnabruck, Germany
3. Prof. Niels E.Christensen (chairman), University of Aarhus, Denmark
4. Prof. Dr.R.Evarestov, St.Petersburg University, Russia
5. Prof. Claes – Goran Granqvist, Uppsala University, Sweden
6. Prof. Dr.M.Kirm, University of Tartu, Estonia
7. Prof. Andrejs Silins, Latvian Academy of Sciences, Latvia
8. Prof. Sergei Tuituinnikov, Joint Institute for Nuclear Research, Dubna, Russia
9. Prof. Juris Upatnieks, Applied Optics, USA
10. Prof. M. Van de Voorde, Max – Planck – Institute, Stuttgart, Germany
11. Prof. Harald W.Weber, Atomic Institute of Austrian Universities, Vienna, Austria The annual report summarizes the research activities of the ISSP in 2011. The staff of the Institute has succeed in 5 national science grants and in two national cooperation projects with the total financing 159.4 thous. Ls (ca. 223.2 thous. EUR).
In 2005 a the new Law of Science was passed by Parliament of Latvia. According to this law the state budgetary financing in Latvia for science has to increase yearly per 0.15% from GDP up to reaching a 1% value. The budgetary increase was focused on scientific infrastructure financing and launching of National Research Programmes (NRP).
One of the scientific priorities in Latvia is materialscience. ISSP became coordinating institution for the Materials NRP and collaborates as well in the NRP “Energetics” attracting
286.9 thous. Ls budget in 2011. The infrastructure financing for ISSP in 2010 was 467.1 thous. Ls. and it was partly used also for the salaries of the scientific and maintenance staff of the Institute. (Table 4).
At the end of 2011, more than 50 students, master’s candidates and doctoral candidates worked in our Institute under the supervising of our scientists. The Institute has always strived to be actively involved in student teaching on all levels. During 2006 – 2008 a teaching module “Functional material and nanotechnologies” was introduced in bachelor and master physics curricula. This project was supported by European Social Fund. Many co-workers of the Institute were involved in preparation of lecture courses.
3.5 3.24 2.72 2.5 2.13 1.72 1.59 1.27 1.5 1.69 1.53 1.2 0.5 0.81 0.28 0.25
The main source for international funding were seven EC 7th Framework Programme
- F-Bridge – 18.7 thous. EUR
- Catherine – 17.1 thous.EUR
- 3 EURATOM projects – 20.4 thous. EUR
- NASA-OTM project – 58.1 thous. EUR
- Reemigration grant (G.Vaivars) – 40.0 thous. EUR
Main achievments in 2011:
1. 143 SCI papers published by the staff of Institute;
2. 1 patent application;
3. 13 B.sc. thesis and 4 M.Sc. thesis in physics were defended under the supervision of our scientists;
4. E.Elsts, S.Fomins, J.Hodakovska, M.Shorohovs and J.Proskurins were acquired degree of doctor of physics (PhD);
5. The formation of “National Research Centre” for nanostructures and multifunctional materials, constructions and technologies by the ISSP.
Many thanks to everybody who contributed to this report as well as to the organizations that supported the Institute financially: Science Department of the Latvian Ministry of Education and Science, Latvian Council of Science, University of Latvia, EC 7th Framework Programme, Programme of EU Structural funds, COST Programme, and to many foreign Universities and institutions for cooperation.
Research Area and Main Problems
1. Magnetic resonance (EPR, optically detected EPR) investigations of the structure of the intrinsic and radiation defects, and their recombination process in some actual wide gap scintillator, x-ray storage phosphor and dosimeter materials. The scientific cooperation with other magnetic resonance groups, especially with the University of Paderborn, Germany. A contribution to the better understanding of the defects and processes in luminescent detector materials is expected.
2. Synthesis and investigation of oxyfluoride, binary and complex rare earth fluoride nanocomposite materials prospective for the light emitters, detectors and visualization systems with enhanced quantum efficiency. Fluoride compounds activated with lanthanide ions may exhibit emission of photons of greater energy than those absorbed during the excitation (up-conversion of energy). The glass and glassceramics samples were synthesized using conventional methods. Several chemical methods were tried for the synthesis of binary and complex rare earth fluorides. The energy relaxation mechanisms were studied during up-conversion processes by means of spectral and time-resolved luminescence measurements in binary and complex rare earth fluorides containing Er, Eu, Nd ions.
3. Technology of Al-Ga nitride semiconductor heterostructures for light-emitting and laser diodes for violet and ultraviolet spectral regions - the goal of the project is the development of light-emitting diodes and laser diodes for violet and ultraviolet spectral region. The project involves synthesis and design of corresponding new materials on the basis of the third group nitrides, elaboration of the thin film heterostructures and further development of production of multifunctional fotonic devices in joint stock company ”Alfa”.
4. Investigation and characterization of the impurity content in fusion plasmas and reactor hot wall are the main goals of EURATOM project. The objectives of this project require study of the influence of the liquid metal limiter on the main plasma parameters, including concentration of evaporated metal atoms in plasma. Laser spectroscopy techniques are proposed for development of procedures for research of impurities in plasma and plasma facing materials. According to the objectives emission of Ga metal vapours in plasmas during the evaporation of the metal gush has been considered. Density of metal vapours in plasma can be obtained using two spectroscopic methods: the steady state emission of the multiple ionised metal ions and the charge exchange emission during ionization of evaporated metal ions.
5. Laser-induced ablation for analysis of the impurities in plasma facing components as the method for the detection of any chemical element is used for the remote analysis. The major tasks of the present investigation are setting up and testing the equipment for laser ablation spectroscopy and developing the methodology for impurity depth profiling. The investigation is carried out using the plasma facing materials of ASDEX Upgrade tokamak by means of laser-induced ablation spectroscopy and profilometry of the corresponding ablation craters. The experimental set-up for the laser-induced ablation spectroscopy was developed and manufactured. The optimal conditions of the laserinduced ablation of the samples of ASDEX Upgrade divertor plates were found. Plasma emission spectra of these plasma facing components showing a substantial number of impurities were recorded. The impurity elements were determined, and the possible sources of the impurities suggested. The depth of the accumulation of basic impurities (hydrogen, boron) in the surface of the ASDEX Upgrade divertor plates (carbon R6710 tiles) is estimated using plasma emission spectra. Obtained results allows considering the method of the laser-induced ablation spectroscopy to be feasible for rapid analysis of plasma facing materials. With minor modifications, this method can be suggested as an in situ technique for determination the state of the plasma facing components inside the chamber of a thermonuclear fusion reactor.
Latvia Joint stock company “Alfa” Germany
1. University of Rostock, Germany (Prof. H.-J. Fitting).
2. “Aixtron” Achen, Germany
3. Max Plank Institute of Plasma Physics, Garching, Germany Romania