Juris PURANS

Dr.habil.phys. Juris PURANS Head of Laboratory Institute of Solid State Physics, University of Latvia Kengaraga iela 8 Riga, LV 1063 Latvia Phone: +371 6725 1691 Fax:     +371 67132778 E-mail:  xas@latnet.lv

Born: August 29, 1952, Riga, Latvia

Interests:

• X-ray absorption spectroscopy (XAS) with Synchrotron Radiation - Picoscopy (10-12 m)
• Local atomic and electronic structure, dynamics and phase-transitions in transition metal (TM) oxides and chalcogenide: mixed valence state and metal-insulator (MI) phase transitions, small radius polaron formation, charge-density waves (CDW), Jahn-Teller effect)
• Magnetron sputtering and characterisations (XAFS, XRD, Raman, IR, EPR) of advanced materials for electrochromic application: new mixed TM:TM nanocrystalline and amorphous oxides
• Local atomic and electronic structure of superionic TM oxides, solid state electrolytes, glasses (oxide and chalcogenide) and solutions doped with rare-earth (RE) ions

Languages: Latvian, Russian, English, French, Italian, German

Education

• University of Latvia (Faculty of Physics), 1974
• Postgraduate, Institute of Solid State Physics, University of Latvia, 1976-1979
• Dr.phys. (Candidate of Science in former USSR, Ph.D. in Western countries), Institute of Solid State Physics, University of Latvia, 1980
         Thesis: EPR of Disordered Solid State Materials
• Dr.habil.phys., Institute of Solid State Physics, University of Latvia, 1993
          Thesis: XAFS Spectroscopy of Transition Metal Oxides.

Experience

Institute of Solid State Physics, University of Latvia:

• Junior Researcher, Researcher, Senior Researcher, 1974 - 1988
• Leading Researcher, Head of XAFS Group, 1988 - 1998
• Head of EXAFS Laboratory, 1998

Abroad:

• Visiting Researcher, Frascati National Laboratories, International Institute of Nuclear Physics, Roma University, Italy, 1982-1983 (10 months)
• Fellowship for high level scientist "Ministere de la Recherche et de l'Espase pour l'accueil de checheurs éntrangers de haut niveau", LURE (Orsay), France, 1993-1994 (6 months)
• Fellowship for Researcher of CNR, ITC (Trento), Italy, 1995 (2 months)
• Fellowship for Researcher of INFM and Physics Dept., Universita di Trento, Italy, 1996, 1998 (4 months)
• Associate Professor:

- Laboratoure de Reactivite et de Chimie des Solides, Universite de Picardie, France, 1994,1995 (3 months)
- Laboratoure de Spectroscopie Moleculaire et Crisralline, Universite Bordoaux I, France, 1995
- Universita di Roma "La Sapienza", Dip. di Chimica, 1995 (2 months)
- Universite Paris-Sud, France, 1996, 1997 (3 months)
- Physics Dept., Universite Marseille II, France, 1995, 1997 (4 months)

• Senior Visiting Fellowship, Frascati National Laboratories, University of Roma, Italy, 1986-1993

Professional Activities and Memberships

• Head, Latvian Synchrotron Radiation Society, 1997 -
• Member of Committee, Council of Synchrotron Radiation, Zelenograd, Russia, 1988-1993
• Member of Committee, European Synchrotron Radiation Society (ESRS), 1993-1996
• Member, Latvian Physical Society, 1991-
• Member, Union of Latvian Scientists, 1991-

Lectures

• X-ray absorption - Picoscopy. Physics Dept., Université Marseille II, France,1996, 1997
• XAFS study of electrohromic oxides. Uppsala University, Sweden, 1997
• O K-edge XANES study of Hydrogen intercalation in ReO3 and WO3 oxides. 12th International Conference on Solid Compounds of Transition Elements, Sant-Malo, France, 1997

Courses

• X-Ray absorption fine structure data analysis, Université Paris-Sud, France 1995-1996
• Structural methods in condensed matter characterisation, University of Latvia, 1994-1997
• Synthesis, properties, and application of thin films, University of Latvia, 1986-1992
• I was also invited as Associate Professor at French (Paris-Sud, Marseille, Bordoaux I, Amiens) and Italian (Trento, Rome) Universities and delivered lectures on XAFS spectroscopy and a course on X-ray absorption fine structure data analysis.

Recent/Representative Publications

• J.Purans, A.Kuzmin,E.Burattini. Double-electron excitations in L-edges x-ray-absorption spectra of W, Ir and Cs oxide compounds. - Jap.J. Appl.Phys., 1993, vol.32, Suppl. 32-2 64-66.
• A.Kuzmin, J.Purans. A new fast spherical approximation for calculation of multiple scattering contribution in the X-ray absorption fine structure and its application to ReO3, NaWO3 and MoO3. - J. Phys.: Cond.Matter, 1993, vol.5, pp.267-282.
• F.Rocca, A.Kuzmin, J.Purans, G.Mariotto, X-ray absorption spectroscopy study of a Nd3+-exchanged beta"-alumina crystal, Phys. Rev. B, 1994, vol.50, pp.6662-6672.
• J.Purans, A.Kuzmin, Ph.Parent, H.Dexpert. XAFS analysis of the low symmetry octahedral molybdenum and tungsten oxides. - Physica B, 1995, vol.208&209, pp.307-308.
• A.Kuzmin, N.Mironova, J.Purans, A.Rodionov. X-ray absorption spectroscopy study of Ni{c}Mg{1-c}O solid solutions on the Ni K edge. - J. Phys.: Cond. Matter, 1995, vol.7, pp.9357-9368.
• A.Kuzmin, J.Purans, G.Dalba, P.Fornasini, F.Rocca, High-temperature x-ray absorption spectroscopy study of ReO3, J. Phys.: Cond. Matter, 1996, vol.8, pp.9083 - 9102.
• E.Cazzanelli, G.Mariotto, C.Vinegoni, A.Kuzmin, J.Purans. Changes of structural, optical and vibrational properties of WO3 powders after milling and mixing with ReO3. - Proc. Electrochem. Soc., 1996, 96-24, pp.260-274.
• N.Mironova, A.Kuzmin, J.Purans, A.Rodionov. X-ray absorption spectroscopy studies of the off-centre Ni2+ ions in NicMg{1-c}O solid solutions. - Proc. SPIE,1996, vol.2706, pp.168-175.
• J.Purans, A.Kuzmin, C.Guéry. In-situ x-ray absorption fine structure and x-ray diffraction studies of hydrogen intercalation in tungsten oxides. - Proc. SPIE, 1997, vol.2968, pp.174-179.
• A.Kuzmin, N.Mironova, J.Purans. Influence of pd-mixing and magnetic interactions on the pre-edge peak intensity at the Co (Ni) K absorption edge in Co(Ni){c}Mg{1-c}O solid solutions. - J. Phys.: Cond. Matter, 1997, vol.9, pp.5277-5286.
• A.Kuzmin, J.Purans, A.Rodionov. X-ray absorption spectroscopy study of the Ni K edge in magnetron sputtered nickel oxide thin films. - J. Phys.: Cond.Matter, 1997, vol.9, pp.6979-6993.
• A.P.Menushenkov, S.Benazeth, J.Purans, A.Y.Ignatov, K.V.Klementev. Local Structure Anomalies of the BaBi(Pb)O3 system Low Temperatures - an X-ray absorption study. - Physica C, 1997, vol.277(3-4), pp.257-264.
• A.Kuzmin, Obst, J.Purans. XAFS and MD study of Zn2+ local structure in aqueous solutions J. Phys.: Cond. Matter, 1997, vol. 9, pp. 10065-10078.
• S.Banazeth, J.Purans, M.-C.Chalbot, et.al. Temperature and pH dependence XAFS study of GdDOTA and GdDTPA complexes: solid state and solution structure. - Inorg. Chem., 1998, 37, pp.3667-3674
• J.Purans, A.Kuzmin, Ph.Parent, C.Laffon. Study of the electronic structure of rhenium and tungsten oxides on the O K-edge. - Ionic, 1998, 4, pp.101-105
• G.Dalba, P.Fornasini, R.Grisnti, J.Purans. Anharmonicity and thermal expansion in crystalline germanium. - J.Synchotron Rad., 1999, 6, pp.253-254.
• E.Gazzanelli, C.Vinegoni, G.Mariotto, A.Kuzmin, J.Purans. Low temperature polymorphism in tungsten trioxide powders and its dependence on mechanical treatments. - J. Solid State Chem., 1999, vol.123, pp.67-74
• A.Kuzmin, J.Purans. Extended x-ray absorption fine structure spectroscopy of perovskite-type compounds. - In: Defects and Surface - Induced Effects in Advanced Perovskites (eds. G.Borstel, A.Krumins, D.Millers), NATO ASHT, ser.3, vol.77, 2000, Kluwer-Dordrecht, pp.139-144
• J.Purans, A.Azens, C.G.Granqvist. X-ray absorption study of Ce-Ti oxide films. - Electrochim. Acta, 2001, vol.46, pp.2055-2058.
• V.L.Aksenov, A.Y.Kuzmin, J.Purans, S.I.Tiutiunnikov. EXAFS spectroscopy at synchrotron-radiation beams [Review] - Phys. Part. Nucl., 2001, vol.32, pp. 675 - 707.
• A.Kuzmin, J.Purans, R.Kalendarev, D.Pailharey, Y.Mathey. XAS, XRD, AFM and Raman studies of NiO-WO₃ electrochromic thin films. - Electrochim. Acta, 2001, vol.46, pp.2233-2236.
• G. Moreau, L. Helm, J. Purans, A.E. Merbach. Structural investigation of the aqueous Eu²⁺ ion: Comparison with Sr²⁺ using the XAFS technique. – J. Phys. Chem. A, 2002, vol.106, pp. 3034 - 3043.
• A.Kuzmin, R.Kalendarev, J.Purans. Local structure of Ta-Re mixed oxide thin films studied by x-ray absorption spectroscopy. - Proc. SPIE, 2003, vol.5122, pp.80 - 86.
• A.Kuzmin, R.Kalendarev, J.Purans, D.Pailharey. Iridium L₃-edge and oxygen K-edge x-ray absorption spectroscopy of nanocrystalline iridium oxide thin films. - Proc. SPIE, 2003, vol.5123, pp.215 - 219.
• D.Pailharey, D.Tonneau, A.Houel, A.Kuzmin, R.Kalendarev, J.Purans. Scanning probe microscopy of nanocrystalline iridium oxide thin films. – Proc. SPIE, 2003 vol.5123, pp.267 - 273.
• E.Cazzanelli, M.Castriota, R.Kalendarev, A.Kuzmin, J.Purans. Sputtering deposition and characterization of Ru-doped WO₃ thin films for electrochromic applications. - Ionics, 2003, vol.9, pp.95-102.
• A.Kuzmin, R.Kalendarev, A.Kursitis, J.Purans. Confocal spectromicroscopy of micro- and nano-strustured materials for its development in Latvia. -  Latvian J. Physics & Technical Sci., 2006, N 2 (1), pp. 66-74.

   

Research Projects

• J.Purans (Head of Project). X-Ray Absorption Spectroscopy of Disordered Metal Oxide Compounds and Amorphous Solids. Latvian Council of Science (1991-1996).
• J.Purans (Head of Project). X-Ray Absorption Spectroscopy of Mixed Transition Metal Oxides and Chalcogenides. Latvian Council of Science (1997-2000).
• J.Purans (Head of Project). X-Ray Absorption Spectroscopy of Itercalated Transition Metal Oxides. ( LV 8001 and LJ 8001) International Science Foundation (1994-1996).
• J.Purans (Head of Projects). XAFS - projects at LURE SRF (Orsay, France): Multiple Scattering study of octahedral molybdenum oxides (1992-1993); In situ XAFS study of phase transitions in WO3-MoO3 system (1994-1996); O K-edge XANES study of ReO3, WO3 and MoO3 oxides (1996- ).
• J.Purans (Head of Latvian Part of Project ). Local structure of beta-alumina doped by RE ions. CNR Collaboration Project: Universita di Trento (CNR, Italy) - University of Latvia (ISSP, Riga ) (1993-1994).
• J.Purans (Head of Latvian Part of Project ). In-Situ XAFS Study of Transition Metal Oxides. PECO International (CE) Project On Applying Synchrotron Radiation. LURE SRF (Orsay, France,1994 - 1997).
• J.Purans (Head of Project). X-Ray Absorption Picoscopy of Advanced Materials. Latvian Council of Science (2001- ).

Last update 10.09.2007