Ph.D. Mariana Stefan

Dr. Mariana Stefan

Senior Researcher II

Telephone :
+40-21-369.01.70 / int.190
Fax :
+40-21-369.01.77
Email :
Education

1986–1991: University of Bucharest, Faculty of Physics


2002: PhD in Physics (Condensed State Physics), University of Bucharest: "Paramagnetic point defects in ionic crystals with structural phase transitions".

Working periods abroad

1995-2007 – visiting scientist in the "Experimental Condensed Matter Physics" Laboratory from the University of Antwerp, Belgium, in research stages cumulating 50 months during the years 1995-2007.


1999 - grant for a one week research visit in the Chemistry Department of the University of Florence in the frame of the ESF "Molecular Magnets" programme.


Short research visits in the frame of bilateral collaboration in the Department of Experimental Physics, University of Turin, Italy (2007) and Department of Optical Crystals, Institute of Physics, Academy of Sciences of the Czech Republic (2008)


Hands-on experience
  • Single crystals growth from melt by the Czochralski and Bridgman techniques
  • Cw and pulse electron paramagnetic resonance (EPR) investigations of bulk and nanostructured materials
  • Analysis of the EPR spectra with dedicated software: SIM, EPRNMR, EasySpin etc.
Research contributions on topics of:
  1. Determination of the structure, quantum state properties and formation mechanisms of the point defects in semiconductor and insulating crystalline materials by multifrequency EPR (Cu2+, Tl0 and Tl2+ paramagnetic centres in Rb2ZnCl4; Fe+ centres in chlorinated SrCl2; Tl2+ and Vk-type centres in PbCl2 and PbBr2; No centers in CVD diamond; intrinsic point defects in cubic BN single crystals and crystalline powders; Mn2+, Gd3+, Nd3+ and Ce3+ ions in PbWO4; Mn2+ in nanocrystalline ZnS, ZnO, hydrozincite ).
  2. EPR investigation of the local crystal field properties in various systems (incommensurate and ferroelectric structural phase transitions in Rb2ZnCl4 and K2ZnCl4, local strains and resonant modes in PbWO4; structural changes of annealed cubic ZnS nanocrystals; lattice ordering and growth of ZnO nanocrystals).
  3. High frequency EPR characterization of molecular magnets: determination of the spectral parameters and the contribution of various interactions to the magnetic anisotropy (Fe4 cluster in Fe4(OCH)6(dpm)6; [Mn(cyclam)Br2]Br; Fe3+ dimer in [Fe2(OCH3)2(dbm)4]).
Researcher ID
http://www.researcherid.com/rid/G-4068-2011