Ph.D. Sergiu Vasile Nistor

Dr. Sergiu Vasile Nistor

Senior Researcher I

Telephone :
(+4021) 369.01.70/ int.190
Email :
Date and place
of Birth

May 30, 1942; Drobeta-Turnu Severin, Romania

Education
  • B.A. and MSc in Theoretical Physics, Babes-Bolyai University, Cluj-Napoca, Romania, 1962 and 1964, respectively (MSc thesis "Covalency effects in optical and ESR spectra of paramagnetic ions in crystals").
  • Ph.D. in Physics, Babes-Bolyai University, Cluj-Napoca, Romania, 1969 (PhD thesis "ESR of point defects in crystalline materials").
  • Postdoc - NSF International Exchange Program, Solid State Division, Argonne National Laboratory, Argonne, Ill., U.S.A., 1971 – 72 (1 year).
Employment History
  • Physics Instructor, Department of Physics, Babes-Bolyai University, Cluj-Napoca, Romania, 1964-68.
  • Physicist (1969-72), Senior Researcher III (1972-76), Institute of Atomic Physics, Bucharest, Romania.
  • Senior Researcher III and Head of Laboratory "Nuclear Materials", Institute of Atomic Physics, Magurele-Bucuresti, Romania (1976-77).
  • Senior Researcher III (1977-90), Senior Researcher II (1990-92), Senior Researcher I (1992-96), Group Leader (1977-96), Institute of Physics and Technology of Materials, Magurele-Bucuresti, Romania.
  • Senior Researcher I and Head of Laboratory "Microstructure of Defects in Solid Materials", National Institute of Material Physics, Magurele-Bucuresti, 1997 - 2009.
  • Senior researcher I, Head of the "Center for advanced ESR techniques- CetRESav", National Institute of Material Physics, Magurele-Bucuresti, 2009-present.
  • Associate Professor, Dept. of Physics, Univ. of Bucharest, Romania, 1999 - present.
Research and Development Experience and Achievements
  •    It covers a broad range of research activities from theoretical investigations in the ESR/optical spectra properties, through experimental studies (crystals growth, development of ESR techniques, ESR and optical investigations of radiation effects and defects in wide band gap insulating and semiconducting crystals, as well as of paramagnetic impurities in various solid materials and biomolecules), up to the industrial development of ultratransparent materials and transmissive optical components for very high power CO2 lasers, ultrahard materials, catalysts and photochromic glasses. The original contributions in the fields of radiation physics, ESR spectroscopy, solid-state physics and materials science and technology, obtained along a + 40 years of research activity have been reported in + 200 papers published mainly in refereed scientific journals and international conference proceedings, including more than 20 invited/plenary lectures at international physics conferences and schools and 13 review papers. The original contributions of industrial interest are protected by 7 patents. More than 700 citations (excluding self-citations) of these results have been identified in various communications, papers and books.
  • Paramagnetic point defects and radiation effects in crystalline materials.
    • Discovery and ESR analysis of the Tl0(1) laser active center in KCl and of other np1 (M0 and Me+ type) centers in alkali halide crystals
    • Discovery and study of several classes of p-type paramagnetic centers produced by irradiation: the np1 site-switched centers, the 6p3 atomic Bi0, negative Pb- and dimmer Tl2+ and Pb23+ centers in alkali and alkali earth chloride crystals.
    • First experimental observation of electron self-trapping in an ionic crystal (PbCl2), resulting in the paramagnetic Pb23+ molecular center with electron configuration complementary to that of the well known hole self-trapped Vk centers in alkali halides.
    • Production and ESR/ENDOR study of several new radiation induced paramagnetic impurity centers in insulating crystals: O- in doped NaCl, Fe+ in ThO2 ; Fe3+ and Fe+ in NaCl, LiCl and SrCl2 ; Fe3+ in CdCl2 ; U3+ in CaF2; Tl2+ in PbCl2 and SrCl2 and Rb2ZnCl4 ; Cu2+ and Cd+ in Rb2ZnCl4, CO2- and CO33- in CaCO3 (calcite).
    • Discovery of radiation induced interstitialization of Fe3+ ions in chlorinated LiCl and NaCl single crystals and of new electron and hole trapping centers at Fe2+ impurities in chlorinated alkali and alkali earth chloride crystals (LiCl, NaCl, SrCl2).
    • First identification of paramagnetic negative cation-type Pb- centers in an electrolytically colored crystal (KCl).
    • Observation of the unconventional localization of Fe2+/Fe+ ions in chlorinated fluorite type SrCl2 crystals. Evidence of the Fe+ ion off-center displacement and of the presence and movement of "as-grown" chlorine interstitials.
    • Using the np1 –type color centers as paramagnetic probes for investigating the structural phase transitions (SPT). The case of the low temperature SPT in Rb2ZnCl4 single crystals.
  • Electron Spin Resonance (ESR). Theory and experimental techniques
    • The first identification and interpretation of the ESR hyperfine forbidden transitions of Mn2+ ions in polycrystalline materials.
    • Contributions to the theory of energy levels and ESR transitions for O- (6p3) centers in orthorhombic crystal fields.
    • High order perturbative calculations of the energy levels and ESR transitions for 6S ions in various noncubic crystal fields.
    • Development of low temperature ESR microwave cavities. First reported application of Gunn diodes in ESR spectroscopy.
  • Materials characterization by ESR and optical spectroscopy (optical and semiconducting crystals, phototropic glasses, molecular sieves and catalysts, superhard CVD diamond films and cubic BN crystals, scintillators, luminescent and laser active materials, proteins).
    • ESR characterization of paramagnetic impurities (Cu2+, Mn2+) in molecular sieves.
    • ESR and optical study of Cu2+ ions in silver based phototropic glasses. New model of copper based phototropic centers.
    • Original ESR based method of determining the catalytic activity of Ti3+ based Ziegler-Natta catalysts.
    • Defect characterization and impurity distribution/localization in superhard materials (CVD diamond thick films and cubic BN) by structural and (ESR , optical) spectroscopy techniques.
    • ESR studies of new paramagnetic impurities - ionic crystal hosts systems: Fe3+ in LiF and calcite, Gd3+ in ThO2 and Yb3+ in SrF2, Mn2+ in layered CdCl2. Localization and interaction of Mn2+, Gd3+, Ce3+, Nd3+ impurity ions with the crystal lattice host of PbWO4 high energy particles scintillator.
    • Determination by ESR spectroscopy of the local coordination of the iron in the heme complex and of the NO-binding properties of neuroglobin, a newly discovered heme protein in the brain of mammals.
    • Determination of the correlation between N and H impurities content and extended defects density in CVD grown polycrystalline diamond by correlated structural (TEM) and spectroscopy (ESR and optical) investigations.
    • Highly accurate spin Hamiltonian parameters of substitutional Mn2+ ions in ZnS single crystals with pure cubic (sphalerite) structure.
    • Observation and characterization by multifrequency ESR of the first point defects in wide band-gap semiconductor and superhard cubic BN crystalline powders and single crystals.
  • Nanostructures and nanophases in crystalline wide band-gap materials.
    • Formation and spatial distribution of nanosilver (colloidal) silver particles in KCl crystals.
    • Observation of size induced changes into the ODMR spectra of AgCl particles in the KCl crystal matrix.
    • Improving the crystal quality of nanocrystalline ZnS with cubic structure by self-assembling.
    • The model of preferential localization of the substitutional Mn2+ activating ions in the cubic ZnS quantum dots lattice next to an extended stacking defect. The proposed ELDA (extended lattice defects assisted) doping mechanism which explains the high doping levels observed in II-VIB nanocrystals prepared by colloidal chemistry.
    • First determination of localization and related optical properties of Mn2+ surface centers in cubic ZnS small nanocrystals.
  • Single crystals growth and characterization.
    • Optical quality single crystals growth (patented procedure) of ultrapure (for high IR laser optics and spectroscopy) and heavily doped alkali and alkali earth halides, to be employed as active media for tunable lasers with color centers, with specially designed and built equipment.
    • Single crystals growth of layered compounds, II-VI and III-V semiconductors, high Tc superconductors, low symmetry ionic compounds without/with structural phase transitions. The resulting crystals have been structurally characterized by X-ray diffraction and electron microscopy techniques and employed in various ESR and optical studies.
  • Interaction of very high power laser beams with IR transparent materials.
    • Development of the most sensitive method and device for measuring very small optical absorption coefficients (calorimetry with thermistors).
    • New correlations between surface optical absorption and laser damage threshold in optically transparent materials (NaCl, KCl, ZnSe).
  • Development of techniques and equipment for assessment and preparation of large ingots of single crystalline, ultratransparent KCl and NaCl.
    • Development of techniques and equipment based on an original crystal growth procedure (IRA – injection of reactive atmosphere, patented) for the preparation of large (> 2 kg weight, 110 mm diameter) single crystal ingots of ultratransparent NaCl and KCl, of high power CO2 laser optics quality
    • Methods and devices for the measurement of the critical parameters in high power laser optics (homogeneity, optical absorption coefficient and laser damage threshold at 10.2 µm ).
    • Techniques for the production and quality assessment of plan-parallel windows from ultratransparent NaCl and KCl single crystalline material with diameters of up to 100 mm for high power cw and pulsed CO2 lasers.
Managerial Research and Development Experince
  • Coordination of + 34 research original contracts/grants obtained on a competitive basis from various national (Romanian) sources (Research Agencies, Companies).
  • Preparation and execution (co-promotor) of 6 international joint research projects obtained on a competitive basis with international participation and funding.
  • Group leader of the Research Group for Optical Materials in the Institute of Physics and Technology of Materials, Bucuresti, Romania (1977 – 1997).
  • Chief of Laboratory in the Institute of Atomic Physics (1976-77) and in the National Institute of Material Physics, Bucuresti, Romania (1997-2009).
  • Organization and management of research laboratories for Optical Spectroscopy, Single Crystal Growth and Characterization by Analytical and Structural methods.
  • Organization and management of a pilot scale production unit of transmissive components for infrared spectroscopy and high power CO2 laser optics at the Institute of Physics and Technology of Materials, Bucuresti, Romania (period 1982 - 1989).
  • Organization and equipping (with funding from several grants/research projects obtained on a competitive basis) of the "Center for advanced ESR/EPR techniques – CetRESav (www.cetresav.infim.ro) ", in the National Institute of Materials Physics, Magurele, Romania ( period 2006-2010).
Leaves of Absence
  • Solid State Division, Argonne National Laboratory, Argonne, Ill., U.S.A., NSF exchange postdoc, Febr. 1971 – Febr. 1972.
  • University of Antwerp (UIA), Dept. of Physics, Antwerp, Belgium, Visiting Researcher, 1976, 1978, 1981, 1984, 1986, 1988, 1990, (2-3 months each time).
  • University of Paderborn, Dept. of physics (FB-6 Physik), Paderborn, Germany, DAAD Senior Visiting Researcher, Dec.1991- Febr.~1992 (3 months).
  • University of Antwerp (UIA), Dept. of Physics, Antwerp, Belgium, Senior Visiting Researcher (Belgian Ministry of Science Policy-DPWB grant), June 1992 - July 1993 (1 year).
  • University of Antwerp (UIA), Dept. of Physics, Belgium, EC Research Fellow, Sept 1993 - Nov. 1993 (3 months).
  • Univ. of Antwerp (UIA), Dept. of Physics, Antwerp, Belgium, Visiting Senior Researcher, (personal invitation from prof. D. Schoemaker), Dec. 1993 - July 1995 (18 months).
  • Univ. of Antwerp (UIA), Dept. of Physics, Antwerp, Belgium, Visiting Research Professor, Co-director of two competitive international research projects in the frame of the scientific and technological agreements Romania - Belgium/Flanders, Aug. 1998 - Nov. 2002 (5 years).
  • Visiting professor, Ecole Superieure de Physique et Chimie Industrielle de Ville du Paris, Paris, France, April-May 2002 (2 months).
  • Visiting Research Professor, University of Antwerp (UA), Department of Physics, Belgium, 2003-2009 (3-4 months each year)
Affiliations - Honors
  • Romanian Physical Society (member since 1970).
  • American Physical Society (member since 1980).
  • BENELUX EPR Society (member since 1993).
  • Dragomir Hurmuzescu Award of Physics of the Romanian Academy (1971).
  • The New York Academy of Sciences (several invitations, since1984), the American Association for the Advancement of Science (several invitations, 2001 -2011), The American Chemical Society (2011).
  • Included in "Marquis Who's Who in the World" (19th ed., 2000-); Huebners Who is Who in Romania, 2nd ed. 2007.
  • Invited lecturer at + 18 national and international conferences and schools of physics.
  • Member of the International Advisory Committee - International Conferences on Defects in Solids (Nordkirchen, Germany-1992, Winston-Salem, U.S.A-1996, Johannesburg, South Africa - 2000, Riga, Latvia – 2004; Aracaju-Brasil, 2008; Pecs-Hungary, 2010; Santa Fe – USA , 2012).
  • Scientific referee at prestigious journals: Physical Review Letters and Physical Review B, Physica Status Solidi, Solid State Communications, Diamonds & Related Materials, American Mineralogist.
  • Expert-evaluator of DG Research-Directorate L. Science, Research & Development of the European Commission (since 2000).
  • Member of the Board of Editors, Romanian Reports in Physics (since 2003).
  • Guest Editor, Physica Status Solidi a201 (11) 2004 (special issue).