Kruminsa.JPG (8219 bytes) Professor Andris KRUMINS
Institute of Solid State Physics, University of Latvia
Kengaraga iela 8
Riga, LV 1063

Phone +371 67261414
Fax +371 67132778

Born: March 31, 1943, Talsi, Latvia


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.



Honours and Awards

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Courses (University of Latvia)

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Last update 21.03.2005