Andris KRUMINS

Professor Andris KRUMINS Vice-Director Institute of Solid State Physics, University of Latvia Kengaraga iela 8 Riga, LV 1063 Latvia Phone +371 67261414 Fax +371 67132778 E-mail: krumins@latnet.lv

Born: March 31, 1943, Talsi, Latvia

Interests:

• Physics of Ferroelectrics
• Phase Transitions
• Material Science and Technology
• Photonics, Optical Information Technology
• Nanomaterials and Nanotechnology
• Smart Materials and Structures

Brief description of main research:

First, I have studied the dynamics of polarization reversal in ferroelectric solid solutions in the region of phase transitions. We have a special interest in solid solutions with diffused phase transitions. We aim at understanding the mechanism of diffused phase transitions.

Since 1970, our main interest has been transparent ferroelectric ceramics (TFC). We have studied in detail the physical and technological requirements in order to develop TFC on a base of lanthanum modified lead zirconate titanate (PLZT). The criteria for the search for new compositions have been defined. In addition to the ferroelectric properties of PLZT ceramics, we have studied the electronic properties (light absorption, scattering, luminescence, photoconductivity and dark conductivity). Special emphasis was put on control of the structure and properties of the surface layer of PLZT.

During my stay in Switzerland, I studied the holographic recording properties in potassium niobate single crystals. We have found that the diffraction efficiency and holographic gain could be described by the dynamic theory of holographic recording. The main mechanism of holographic recording was due to the diffusion of photoexcited carriers. Later, we studied photorefraction and holographic recording in PLZT ceramics. We found that the space charge field responsible for the photorefraction is limited by trap or donor density due to the high value (1000) of the static dielectric constant. The specific properties of the holographic recording close to the diffuse phase transition have been revealed. Recently, together with colleagues from Japan, we have discovered a spontaneous ferroelectric relaxor phase transition as well as optical bistability in PLZT ceramics.

Languages: English, German, Russian, Latvian.

Education:

• University of Latvia (Faculty of Physics and Mathematics) cum laude, 1966
• Dr.phys. (Candidate of Science in former USSR, PhD in Western countries), University Rostov-on-Don, Russia, 1970
• Dr.habil.phys. (Doctor of Science in former USSR), Latvian Academy of Sciences, 1986

Experience:

• Junior Researcher, Senior Researcher, Ferroelectric Physics Laboratory, University of Latvia, 1964-1977.
• Scholarship holder, Swiss Federal Institute of Technology (Switzerland), 1977-1978.
• Head of Laboratory, Head of Division, Deputy director Institute of Solid State Physics, University of Latvia, 1978-1986.
• Visiting researcher, University of Osnabruck (Germany), 1986-1987.
• Vice-Director (1987-1992; 1999- ) and Director (1992-1999), Institute of Solid State Physics, University of Latvia
• Guest Professor, Kyoto University (Japan), 1993-1994.
• Professor, University of Latvia 1990-
• Scientific Coordinator, Excellence Centre of Advanced Material Research and Technology at the Institute of Solid State Physics, University of Latvia (CAMART), European Commission, 2001 – 2003

Honours and Awards

• Corresponding Member, Latvian Academy of Sciences, 1999-2001
• Full Member, Latvian Academy of Sciences, 2001
• Member, European Academy of Sciences (Section of Physics with the citation  " For outstanding contributions to Physics and fundamental developments in the field of nano-technologies")

• Member of Senate, University of Latvia, 1995 –
• Member, International Society for Optical Engineering (SPIE)
• Member, American Optical Society
• Member, Latvian Physical Society
• Member of the International Advisory Board of the:

- European Conference on Applications of Dielectrics,
- European Meeting on Ferroelectricity,
- International Symposium on Ferroic Domains and Mesoscopic Structures

• Chairman of the International Conferences on:

- Transparent Ferroelectric Ceramics (1985, 1988)
- Electronic Ceramics (1990),
- Advanced Optical Materials and Devices (1996, 2002),
- 5^th Euroconference on Application of Polar Dielectrics (2000),
- NATO ARW “Defects and Surface Induced Effects in Advancd Perovskites” (1999).

• Editor:

- Ferroelectrics, vol.69, Nos.1/2, 1986; Ferroelectrics, vol.90, 1989
- Optical Inorganic Dielectric Materials and Devices, Proc. SPIE vol. 2967, 1997, vol. 5123, 2003.

Courses (University of Latvia)

• Physics of Dielectrics, 1990-
• Phase Transitions, 1993-1997
• Polar Dielectrics and Applications, University of Latvia, 1990 –
• Principles of Material Science, 1995 -
• Materials in Nature and Industry, 1999 -

Recent/Representative Publications:

• V.Ta.Shur, G.G.Lomakin, E.L.Rumyantsev, S.S.Beloglazov, D.V.Pelegov, A.Sternberg, A.Krumins. Fractal clusters in relaxor PLZT ceramics: evolution in electric field. – Ferroelectics, 2004, vol.299, pp.75-81.
• A.Sternberg, A.Krumins, K.Kundzins, V.Zauls, I.Aulika, L.Cakare. Irradiation effects in lead zirconate thin films. - Proc. SPIE, 2003, vol. 5122, pp. 345-350.
• L.Shebanovs, A.Sternberg, V.Zaiuls and A.Krumins. Somr new ceramics and thin films of Pb (B3+, Nb)TiO3- PbTiO3 systems. - Ferroelectrics, 2002,  vol.267, pp.271-277.
• M.Knite, A.Krumins, D.Millers. Laser - Comoletric Study of fundamental absorption edge in Pb, La(Zr, Ti) O (PLZT) Perovskite. - In: Induced Effects in Advanced Perovskites, Kluwer Academic Publ., 2000, vol.77, pp.405-410.
• V.Shur, G.Lomakin, V.Kuminov, S.Beloglazov, S.Slovikovsky, A.Krumins and A.Sternberg. Kinetics of reversal field induced transformations in relaxor (6-8)/ 65/35 PLZT ceramics.- J. Korean Physical Society, 1998, vol. 32, pp. 985-988.
• R.Silvennoinen, K.E. Peipouen, A.Krumins, J.Rasanen. Optical quality inspection of PLZT ceramics by using CGH-elements. - Optical Materials, 1997, vol. 7, pp. 145-152.
• A.Krumins, Z.Chen, M.Shibata, A.A.Belov. Relaxational optical oscillations in PLZT thermal lenses. Ferroelectrics, 1996, vol.183, pp.171-180.
• A.Krumins, T.Shiosaki, A.Plaude, A.Spule. The domain structure in PLZT (6-8)/65/35 and spontaneous ferroelectric-relaxor phase transition. - Ferroelectrics, 1995, vol.172, pp.111-114
• A.Krumins. Recent developments of electrooptic and electrocaloric materials and devices. - Trans.Mat.Res.Soc.Jpn., 1994, vol.14B, pp.1609-1614.

Research Projects:

• (Head of Project). Phase Transitions in Ferroelectrics-Relaxors. Latvian Council of Science, 1997-1999.
• Head of Project. New Materials for Microelectronics and Photonics - Research Programme. Latvian Council of Science, 1997-2000.
• (Head of Latvian Part of Project). Phase Transitions in PLZT. Joint research project between Nagoya University, Kyoto University (Japan) and University of Latvia, 1994-1996.
• (Scientific Coordinator, Centre of Exellence) . Advanced Materil Research and Technologies, 2001-2003.
• (Head of Cooperative Research Project).  Intelligent Materials and Structures in Microelectronics and Photonics.  Latvian Council of Science , 2001 - 2004
• (Head of Project). Optimisation of Sintering Process, Physical Properties and Polarisation Micromechanisms in Ferroelectrics with Different Degree of Ordering. Latvian Council of Science , 2005 - .

Last update 21.03.2005