| CZECH NANO TEAM | Physics of Nanostructures and Nanotechnologies

Emil Pollert

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Group subject:

Magnetic nanomaterials

Name and Curriculum vitae of contact person:

Emil Pollert (Doc., Ing., DrSc.)

Affiliation:

Institute of Physics, Academy of Sciences of the Czech Republic

Fields of scientific activity:

• Solid state chemistry and physics of the magnetic and superconducting transition metal oxides.

• Preparation and characterisation of magnetic oxides including nanoparticles for applications in medicine and biology (last two years)

• Publications 197 scientific publications, including 122 articles in the impacted international journals, 25 invited lectures at international symposia, 4 patents, more than 1050 references appeared in the literature (SCI)
• The supervisor of 10 successful diploma theses, 5 PhD and CSc theses.

International cooperation:

Institut de Chimie de la Matière Condensée de Bordeaux, France,

CRISMAT Caen, France,

Institute for Physical High Technology Jena, Germany,

Industrial Technology Research Institute, Hsinchu, Taiwan, R.O.C, connected with study stays and short visits.

Granted projects:

• GA ASCR, 1991-1993 "Oxidic sytems with occurrence of superconducting phases"

• GA CR, 1993-1995 "Charge carriers ande chemical bond in superconducting oxides"

• GA CR 1996-1998 "Crystal chemistry of superconducting mercury cuprates"

• GA ASCR 2000-2002 "Oxidic materials with photoinduced insulator-metal transitions"

• PICS (CRISMAT, Caen) – IOP ASCR, 1994 - 1996"Oxydes supraconducteurs à haute température critique: recherch de nouvelles phases, croissance cristalline et études des propriétés physiques"

• CT 94 0080 LLB Saclay – IOP ASCR 1995 – 2000 "Structural studies of superconducting oxides and manganites by neutron scattering"

• CIPA – CT94 – 0185 CISE SpA, Milano, Italy – IEE, SAC, Bratislava – IOP ASCR, 1995 – 1997 "Preparation and characterization of Bi – high temperature suoerconductors for technical applications"

• Barrande 2003-003-1, ICMCB, CNRS – IOP, ASCR, 2003-2004 "Les matériaux hybrides magnétiques micro et nanométriques pour l´utilisation en biologie et en médecine"

Selected publications from last 5 years:

• M.Maryško, Z.Jirák, M.M.Savosta, E.Pollert, Y.Tomioka, Y.Tokura: Magnetic phase transitions of Pr0.65Ca0.21Sr0.14MnO3 and Pr0.65Ba0.35MnO3 single crystals, Journal of Magnetism and Magnetic Materials 226-30, 592-593 (2001)

• Takuya Satoh, Yoshinao Kikuchi, Kenjiro Miyano, E.Pollert, J.Hejtmánek, Z.Jirák: Irreversible photoinduced insulator-metal transition in the Na-doped manganite Pr0.75Na0.25MnO3, Physical Review B 65, 125103-1-4 IF 3.07 (2002)

• E.Pollert, Z.Jirák, J.Hejtmánek, A.Strejc, R.Kužel, V.Hardy: Detailed study of the structural and magnetic transitions in Pr1-xSrxMnO3 single crystals (0.48< x<0.57), Journal of Magnetism and Magnetic Materials 246, 290-296 (2002)

• E. Pollert, J. Hejtmánek, K. Knížek, M. Maryško, J.P. Doumerc, J.C. Grenier, J. Etourneau: Insulator – Metal transition in Nd0.8Na0.2MnO3 perovskites, Journal of Solid State Chemistry 170, 368-373 (2003)

• E. Pollert, J. Hejtmánek, Z. Jirák, K. Knížek, M. Maryško: Influence of Co doping on properties of Pr0.8Na0.2Mn(1 y)CoyO3 perovskites, J. Solid State. Chemistry174 , 466-470 (2003)

Group members:

Emil Pollert, Pavel Veverka, Karel Knížek, Eva Hadová, Miroslav Maryško, Zdeněk Frait, Dagmar Fraitová, Rastislav Malych

Main Research Subjects:

The research is aimed on the development of new magnetic nanocomposites using mixed magnetic oxides or ferromagnetic metals of selected intrinsic properties with respect to the relation between their size and morphology and magnetic properties. The study is oriented on the use of magnetic particles as contrast materials for MRI, magnetic hyperthermia, magnetic separation, the use of nanosystems for high frequency applications, and on the magnetization dynamic processes in nanoparticle systems.
Magnetic particles have to be monodisperse and with a controllable size. An attention will be paid to understanding of the synthesis conditions including two steps, formation of a precursor via “solution chemistry” and the subsequent thermal treatment; mechanism of the reaction will be elucidated.

Selected Specific Equipment (IOP):

Classical equipment for the soft-chemistry, various tube and muffle furnaces allowing thermal treatment under precisely defined conditions (p(O2), T)

Equipment and methods of characterization: SQUID magnetometr, 4 – 400 K, 0 – 5 T, X- ray powder diffractometer,

Chemical and microstructural analysis: classical chemical analysis, electron microprobe analysis combined with scanning electron microscopy,

Vibrating magnetometer 4 – 800 K, 0 – 2T; Multifrequency ferromagnetic resonance spectrometer, 8 – 108 GHz, 4 – 600 K; Local stray fields electron paramagnetic resonance detector.

External cooperation: High resolution scanning electron microscopy combined with special MaxRay XX WDS Spectrometry and EDS Spectrometry, HREM.

Remark:

The study requires a close cooperation of experts in magnetism, chemistry, biology and medicine namely from several of research groups:

• laboratory with long-term experiences in physics and chemistry of mixed valence transition metal oxides of outstanding magnetic and electric properties (IOP ASCR)

• laboratory of surface magnetism with deep experience in magnetic studies of micro- and nanoparticle systems (nanofilms, .nanoparticle assemblies) (IOP ASCR)

• group of polymer particles specializing in the design of particulate materials by heterogeneous polymerization techniques (IMC ASCR, ICMCB CNRS)

• team oriented on medical and biological application of these materials, fundamental studies as well as clinical examinations (IKEM, Université Bordeaux II)

• group with major expertise in the magnetic and structural characterization analysis of low-dimensional systems, Institute of Physics (group Farle) of Universität Duisburg- Essen, Duisburg, FRG

• group of magnetism with several years of experience in the synthesis of colloidal particles and their optical and structural characterization at Center of Advanced European Studies and Research, Bonn, FRG.

Additional recent selected publications by group members:

• U.Wiedwald, M. Spasova, E. L. Salabas, M.Ulmeanu, M. Farle, Z.Frait, A.FraileRodriguez, D. Arvanitis, N. S. Sobal, M. Hilgendorff, M. Giersig: Ratio of orbital-to-spin magnetic moment in Co core-shell nanoparticles, Phys. Rev. B 68, 064424 (2003)

• J. Lidner, K. Lenz, E. Kosubek, K. Baberschke, D. Spoddig, R. Meckenstock, J. Pelzl, Z.Frait, D.L. Mills: Evidence for "Non-Gilbert-Type' Damping of the Magnetic Relaxation in Ultrathin Ferromagnets: Importance of Magnon-Magnon Scattering, Phys.Rev.B 68, 060102 (2003)

• M. Ulmeanu, C. Antoniak, U. Wiedwald, M. Farle, Z. Frait, S. Sun: Composition dependent ratio of orbital to spin magnetic moment in structurally disordered FexPt1-x nanoparticles, at print Phys.Rev.B (2004)