Linards SKUJA

Dr. habil. phys. Linards SKUJA Leading Researcher Institute of Solid State Physics, University of Latvia Kengaraga iela 8 Riga, LV 1063 Latvia Phone: +371 6726 0756 Fax: +371 6713 2778 E-mail: skuja_at_latnet.lv

Born: 1952, Riga, Latvia

• Point defects in crystalline and amorphous solids
• Nature of non-crystalline solids
• Applications of glassy materials, particularly silicon dioxide-based glasses in optoelectronics
• SiO₂-related nanostructures and surface phenomena
• Optical, magnetic resonance and X-ray fluorescence spectroscopy
• Applications of computers in physical experiment

The general research interests concern glassy/amorphous materials for optics and electronics. The main focus is on oxide materials based on SiO₂ and GeO₂. The motivation for studying these materials is provided by the outstanding physical properties of glassy SiO₂ and the key role it plays in a number of modern applications: low-loss optical fibers for communications, ultraviolet and high-power laser optics, insulating oxide layers in silicon-based microelectronics, radiation resistant optical glasses etc. Our work mainly concerns point defects in these materials, their structure, generation mechanisms and optical properties, their impact on practical applications and devices.

Languages: Latvian, English, German, Russian

• University of Latvia (Faculty of Physics and Mathematics), 1974
• Postgraduate, University of Latvia, 1977-1980
• Dr.phys. (Candidate of Science in former USSR, PhD in Western countries), Institute of Physics, Latvia, 1980
• Dr.habil.phys., Institute of Solid State Physics, University of Latvia, 1994

• Engineer, Junior Researcher, Laboratory of Semiconductor Physics, University of Latvia, 1972-1977.
• Junior Researcher, Senior Researcher, Leading Researcher, Head of Laboratory,  Institute of Solid State Physics, University of Latvia, 1980 –

• Visiting scientist in Torino University, Italy (1989)
• Alexander-von-Humboldt Fellow, University of Muenster, Germany, 1991-1992, 1995.
• Visiting scientist, Nagoya University, Japan 1994
• Research scientist, German Federal Institute of Natural and Engineering Sciences
  (Physikalisch-Technische Bundesanstalt, PTB), Braunschweig, Germany 1995-1998.
• Visiting professor Tokyo Institute of Technology, Yokohama, Japan 1999
• Visiting scientist/visiting professor, Tokyo Institute of Technology, 2000-2011 (~2-3 months per year)

• Corresponding Member, Latvian Academy of Sciences, 1996
• Full Member, Latvian Academy of Sciences, 2003
• The Latvian Academy of Sciences Edgar Silins Prize in Physics, 2003.

• Member, Latvian Physical Society.

Recent Publications (2006-2011):

1. K. Kajihara, M.Hirano, L.Skuja, H.Hosono, Role of Interstitial Voids in Oxides on Formation and Stabilization of Reactive Radicals: Interstitial HO₂ Radicals in F₂ -Laser-Irradiated Amorphous SiO₂. J. Amer.Chem.Soc., v.128, p.5371-5374 (2006).
2. K. Kajihara, M.Hirano, L.Skuja, H.Hosono, Interstitial OH radicals in F₂-laser-irradiated bulk amorphous SiO₂. J.Phys.Chem.B v.110, p.10224-10227 (2006).
3. L.Skuja, K. Kajihara, M. Hirano, A.. Saitoh,  H. Hosono, An increased F₂ laser damage in "wet" silica glass due to atomic hydrogen: a new hydrogen-related E’-center. J. Non-Crystalline Solids, v.352, p.2297-2302 (2006).
4. K. Kajihara, L.Skuja, M.Hirano, H.Hosono, Vacuum-ultraviolet absorption of interstitial O₂ and H₂O molecules in SiO₂ glass. J. Non-Crystalline Solids, v.352, p.2303-2306 (2006).
5. K. Kajihara, L.Skuja, M.Hirano, H.Hosono, In situ observation of the formation, diffusion, and reactions of hydrogenous species in F₂ -laser-irradiated SiO₂ glass using a pump-and-probe technique. Phys. Rev. v. B74, p.094202(1-11) (2006).
6. K. Kajihara, M. Hirano, L.Skuja, H.Hosono Reactivity of SiCl and SiF groups in SiO₂ glass with mobile interstitial O₂ and H₂O molecules. J. Non-Crystalline Solids, v.353, p.514-517 (2007).
7. K. Kajihara, M. Hirano, L.Skuja, H.Hosono Formation of Intrinsic Point Defects in Fluorine-doped Synthetic SiO₂ Glass by ⁶⁰Co gamma-ray Irradiation  Chemistry Letters Vol.36, No.2, p.266-267 (2007).
8. L. Skuja, K. Kajihara, M.Hirano, H.Hosono. Fluorine laser-induced silicon hydride Si-H groups in silica. J. Non-Crystalline Solids, v.353, p.526-529 (2007).
9. K.Kajihara, M.Hirano, Y.Takimoto, L.Skuja, H.Hosono. Diffusion of nitrogen molecules in amorphous SiO₂ . Appl.Phys. Lett. v.91, p.071904 (1-3) (2007).
10. L. Skuja, K. Kajihara, M.Hirano, H.Hosono.  Ultraviolet absorption of hydrogen-related species in glassy silica, Physics and Chemistry of Glasses, European Journal of Glass Science and Technology B vol.48, No3, p.103-106 (2007).
11. L. Skuja, K. Kajihara, M.Hirano, H.Hosono. Hydrogen-related radiation defects in SiO₂ - based glasses. Nuclear Instruments and Methods in Physics Research Section B. v.266, No12-13, p.2971-75 (2008).
12. K. Kajihara, T. Miura, H. Kamioka, A.Aiba, M. Uramoto, Y. Morimoto, M. Hirano, L. Skuja, H. Hosono, Diffusion and reactions of interstitial oxygen species in amorphous SiO₂: A review. J.Non-Crystalline Solids v.354, p.224-232(2008).
13. K. Kajihara, M. Hirano, L. Skuja, H. Hosono, Intrinsic defect formation in amorphous SiO₂ by electronic excitation: Bond dissociation versus Frenkel mechanisms, Phys. Rev. B78, p.094201(1-8) (2008).
14. K. Kajihara, M. Hirano, L. Skuja, H. Hosono, ⁶⁰Co gamma-ray-induced intrinsic defect processes in fluorine-doped synthetic SiO₂ glasses of different fluorine concentrations. Materials Science and Engineering: B  v.161 p.96-99 (2009) ( doi:10.1016/j.mseb.2008.11.002).
15. K. Kajihara, T. Miura, H. Kamioka, M. Hirano, L. Skuja, H. Hosono, Oxygen exchange at the internal surface of amorphous SiO₂ studied by photoluminescence of isotopically labeled oxygen molecules.  Phys. Rev. Letters v.102, 175502(2009).
16. K. Kajihara, T. Miura, H. Kamioka, M. Hirano, L. Skuja, H. Hosono, Isotope Effect on the Infrared Photoluminescence Decay of Interstitial Oxygen Molecules in Amorphous SiO₂ . Applied Physics Express vol.2, p. 056502 (2009).
17. K. Kajihara, T. Miura, H. Kamioka, M. Hirano, L. Skuja, H. Hosono, Photoluminescence study of diffusion and reactions of ¹⁸O-labeled interstitial oxygen molecules in amorphous SiO₂.  Electrochemical Society Transactions v.25 (9) p.277-285 (2009).
18. K.Kajihara, T.Miura, H.Kamioka, M.Hirano. L.Skuja, H.Hosono, Diffusion of oxygen molecules in fluorine-doped amorphous SiO₂ . Materials Science and Engineering: B173 p.158-161 (2010)(doi:10.1016/j.mseb.2010.01.002).
19. K.Kajihara, T.Miura, H.Kamioka, M.Hirano. L.Skuja, H.Hosono, Exchange between interstitial oxygen molecules and network oxygen atoms in amorphous SiO₂ studied by ¹⁸O isotope labeling and infrared photoluminescence spectroscopy. Phys.Rev. B83, 064202 (2011).
20. L.Skuja, K.Kajihara, M.Hirano, H.Hosono, Crucial dependence of excimer laser toughness of “wet” silica on excess oxygen J. Non-Crystalline Solids v.357 p.1875–1878 (2011)  (doi:10.1016/j.jnoncrysol.2010.12.047).
21. K.Kajihara, M.Hirano, L.Skuja, H.Hosono Oxygen-excess amorphous SiO₂ with ¹⁸O-labeled interstitial oxygen molecules J. Non-Crystalline Solids v.357, No 8-9,  p.1842-1845(2011) .
22. K.Kajihara, M.Hirano, L.Skuja, H.Hosono Frenkel defect process in amorphous silica Proc. of SPIE Vol. 8077  80770R-1 (2011).
23. L.Skuja, K.Kajihara, M.Hirano, A.Silins, H.Hosono Effects of temperature on electron paramagnetic resonance of dangling oxygen bonds in amorphous silicon dioxide, IOP Conf. Series: Materials Science and Engineering 23 (2011) 012016
24. L. Skuja, K. Kajihara, M. Hirano, H. Hosono, Visible to vacuum-UV range optical absorption of oxygen dangling bonds in amorphous SiO₂, Phys.Rev.B 84, 205206 (2011) [9 pages]  doi: 10.1103/PhysRevB.84.205206

Research Projects:

• L.Skuja (Head of Project) Study of Point Defects and their Generation in SiO₂ and GeO₂ Based Glasses and Crystals. Latvian Council of Science, (1993 - 1996 )
• L.Skuja (Head of Project) Spectroscopic Studies of Point Defects in Oxide Materials with Different Degree of Structural Disorder. Latvian Council of Science, (1996 – 2000)
• L.Skuja (Head of Project) Investigation of Point Defects in Wide-Gap Glassforming Materials for Microelectronics, Optical Waveguides and Laser Optics. Latvian Council of Science, (2001 - 2004)
• L.Skuja (Head of Project) Study of Optical Properties, their Optimization and Variation Mechanisms in Glassy Materials for Ultraviolet Optics and Fiber Wave-guides. Latvian Council of Science, (2005 - )
• L.Skuja (Leader of the work packet:"Defects in oxide glasses and related materials") within the EC sponsored program "Excellence Center for Advanced Material Research and Technology" (CAMART) in Institute of Solid State Physics
• L. Skuja (local coordinator) of European research-training network "Optical Devices Using Photosensitivity for their Elaboration (2000-2004).

Last update 20.01.2012