Dr. Galina Malovichko

·      Main interests: experimental research of defects in ferroelectrics, non-linear optical materials, electro- and acousto-optical crystals.

·    Main methods of investigation: electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR), optical spectroscopy, and simultaneous EPR + optical absorption spectroscopy.

·     Supplementary experimental methods used: nuclear magnetic resonance (NMR), X-ray structural analyses, dielectric permittivity and conductivity measurements, electron microscopy, different kind of radiation treatment and annealing of crystals in various atmospheres.

·     Main materials studied: electro- and acousto-optical, laser crystals LiNbO3 and LiTaO3, pyroelectric and superionic Li2B4O7, nonlinear optical materials - KTiOPO4, BaTiO3, BaxCa1-xTiO3, virtual ferroelectrics KTaO3.

·      Central purpose of the investigation: determination of the structure of extrinsic, intrinsic and radiation defects and their influence on crystal properties; characterization of materials and optimization of their parameters.

·       Selected publications devoted to nonstoichiometric and stoichiometric lithium niobate and tantalate: selected scientific articles,  selected invited talks,  selected invited lectures. 

·      Recent results: Evolution of conception of intrinsic and extrinsic defects in lithium niobate. Fourth Annual Meeting of the COST Action P2 "Applications of nonlinear optical Phenomena" and Workshop on LiNbO3. Budapest, May 2001 (invited talk).

·      Selected articles to download: EPR, ENDOR, and optical absorption study of Cr3+ centers substituting for niobium in Li-rich lithium niobate crystals. V.Grachev, G.Malovichko.- Physical Review B62, 7779-7790, 2000.  Axial and low-symmetry centers of trivalent impurities in lithium niobate. Chromium in congruent and stoichiometric crystals. G.Malovichko, V.Grachev, E.Kokanyan, O.Schirmer.- Physical Review, B59, 9113-9125 (1999).     Interrelation of intrinsic and extrinsic defects – congruent, stoichiometric, and regularly ordered lithium niobate. G.Malovichko, V.Grachev, O.Schirmer.- Appl. Phys. B 68, 785-793 (1999).               

·      What do I like else?  Coffee, cheese and, of course,  Visual EPR  programs!

Selected scientific articles devoted to nonstoichiometric and stoichiometric lithium niobate and tantalate

  1. Optimization of lithium niobate for advanced applications by variation of extrinsic and intrinsic defect subsystems. G.Malovichko, V.Grachev, E.Kokanyan, O.Schirmer. Ferroelectrics, 258, 131-140 (2001).

  2. EPR, ENDOR, and optical absorption study of Cr3+ centers substituting for niobium in Li-rich lithium niobate crystals. V.Grachev, G.Malovichko.- Physical Review B62, 7779-7790 (2000).

  3.  EPR, NMR and ENDOR study of intrinsic and extrinsic defects in regularly ordered and disordered Lithium Niobate crystals. G.I.Malovichko, V.G.Grachev, E.P.Kokanyan, O.F.Schirmer. Ferroelectrics, 239, 357-366 (2000).

  4.  Electrooptic properties in Fe-doped LiNbO3 crystals as function of composition. K.Chah, M.Aillerie, M.D.Fontana, G.Malovichko. Optics Communications, 176 261-265 (2000).

  5. Axial and low-symmetry centers of trivalent impurities in lithium niobate. Chromium in congruent and stoichiometric crystals. G.Malovichko, V.Grachev, E.Kokanyan, O.Schirmer.- Physical Review, B59, 9113-9125 (1999).

  6.  Interrelation of intrinsic and extrinsic defects – congruent, stoichiometric, and regularly ordered lithium niobate. G.Malovichko, V.Grachev, O.Schirmer.- Appl. Phys. B 68, 785-793 (1999).

  7.  Nonstoichiometry as a powerful tool for photorefractive material optimisation. Lithium Niobate Crystals. G.Malovichko. Proc. of the 7-th Top.Meet. on Photorefractive Materials, Effects and Devices, Denmark, June 27-30 1999, OSA TOPS, 27, 59-66 (1999).

  8.  Electro-optic properties in undoped and Cr-doped LiNbO3 crystals.- K.Chah, M.D.Fontana, M.Aillerie, P.Bourson, G.Malovichko.- Applied Phys. B 67, 65-71 (1998).

  9.  High-resolution electron microscopy investigation of correlated defects in non-stoichiometric lithium niobate. Ch.Leroux, G.Malovichko, G.Nihoul, V.Grachev, C.Boulesteix.- J. Phys. Chem. Solids, v. 59, No 3, pp.311-319 (1998).

  10.  Lattice constants of K and Mg doped LiNbO3. Comparison with nonstoichiometric crystals. G.Malovichko, O.Cerclier, J.Estienne, V.Grachev, E.Kokanyan, C.Boulesteix.- J. Phys. Chem. Solids, v. 56, pp.1285-1289 (1995).

  11.  Characterization of stoichiometric lithium niobate grown from melts containing K2O. G.I.Malovichko, V.G.Grachev, E.P.Kokanyan, O.F.Schirmer, K.Betzler, B.Gather, F.Jermann, S.Klauer, U.Schlarb, M.Wöhlecke.- Appl. Phys., v. A56, 103-108 (1993).

  12.  Improvement of LiNbO3 microstructure by crystal growth with potassium. G.I.Malovichko, V.G.Grachev, L.P.Yurchenko, V.Ya.Proshko, E.P.Kokanyan, V.T.Gabrielyan.- Phys. Stat. Sol. (a), v. 133, No 1, p. K29-K33 (1992).

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Selected invited talks at the international conferences for last two years

1.      Evolution of conception of intrinsic and extrinsic defects in lithium niobate. G. Malovichko – Fourth Annual Meeting of the COST P2 Meeting “Application of nonlinear optical phenomena” and Workshop on LiNbO3, 16-19 May 2001, Budapest, Hungary.

2.      Defects in non-stoichiometric and stoichiometric lithium niobate: the present state-of-the-art and outlook. G.Malovichko. International Conference on Defects in Insulating Materials (ICDIM), April 3-7, 2000, Johannesburg, South Africa.

3.      Structure and interrelation of intrinsic and extrinsic defects in congruent, stoichiometric and regularly ordered lithium niobate. G.Malovichko.-International symposium on Laser, Scintillator and Nonlinear Optical Materials “PHOTONICS MATERIALS for the 21st CENTURY”, 28-31 May 2000, Lyon, France.

4.      Optimization of lithium niobate for advanced applications by variation of extrinsic and intrinsic defect subsystems. G.Malovichko, V.Grachev, E.Kokanyan, O.Schirmer. 5th European Conference on Application of Polar Dielectrics (ECAPD-5), 26-31 August 2000, Riga, Latvia

- Chairman session 5: Photorefraction and Related Phenomena.

5.       Defects in nonstoichiometric and stoichiometric LiNbO3: Present state-of-the-art and perspectives. G.Malovichko, V. Grachev.– International Workshop on Microstructure of Oxide Materials, 13-15 June 2000, Osnabrück, Germany.

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Selected invited lectures

·        Georgia University, Athens, USA, May 2000.

·        Stanford University, USA, May 2000.

·        Paderborn University, Paderborn, Germany, June 1999.

·        Regensburg University, Regensburg, Germany, February, 1996.

·        Stuttgart University, Stuttgart, Germany, 1995.

·        Universities of Metz, Metz, France, 1994.

·         Aix-Marseille 3 University, Marseille, France, 1993.

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