Multifrequency Elektron spin resonance studies of Collective phenomena in solids  Page description

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Details of project

  
Identifier
43255
Type K
Principal investigator Jánossy, András
Title in Hungarian Kollektív jelenségek multifrekvenciás elektron spin rezonancia vizsgálata szilárdtestekban
Title in English Multifrequency Elektron spin resonance studies of Collective phenomena in solids
Panel Physics 1
Department or equivalent Department of Physics (Budapest University of Technology and Economics)
Participants Fehér, Titusz
Fülöp, Ferenc
Korecz, László
Murányi, Ferenc
Rockenbauer, Antal
Simon, Ferenc
Vannay, László
Starting date 2003-01-01
Closing date 2006-12-31
Funding (in million HUF) 17.518
FTE (full time equivalent) 0.00
state closed project





 

Final report

  
Results in Hungarian
Kollektív jelenségeket vizsgáltunk szilárdtestekben multifrekvenciás elektron spin rezonancia spektroszkópiai módszerrel. - Szupravezetők és rokon mágnesesen rendezett anyagok A ma már „klasszikusnak” számító CuO2 alapú perovszkit szupravezetőkben munkánk a az antiferromágnesség és szupravezető állapotú rendszerek határán levő anyagokra irányult. Részletesen vizsgáltuk az elektromos töltés és mágneses spinsűrüség térbeli eloszlását. - Manganit perovszkitok mágnesesen rendezett és töltésrendezett állapotai Három, szerkezetében különböző rendszert vizsgáltunk, melyeknél a legérdekesebb kérdés az elméletileg jósolt inhomogén töltéseloszlás kísérleti kimutatása volt. - Elektron delokalizáció fullerén és szénalapú nanoszerkezetekben Részletesen vizsgáltuk a C59N-nel dópolt C60 rendszert, amely a fullerén félvezetők modellje lehet. Látszólagos egyszerűsége ellenére különleges mágneses és elektromos tulajdonságokat találtunk, melyeket értelmeztünk. A szén alapú nanocsövekbe fullerén spinjelzőt töltöttünk, ami lehetűvé teszi elektromos tulajdonságainak tanulmányozását. A munkát számos külföldi laboratóriummal együttműködve végeztük. Az ESR vizsgálatokat a BME-n fejlesztett, multifrekvenciás és az MTA-KKI 2004-ben felállított Bruker típusú 9 GHz-s ESR spektrométerén végeztük. Eredményeinket neves folyóiratokban közöltük. Megszerveztük a nagyfrekvenciás ESR spektroszkópia SENTINEL Európai Hálózatának zárókonferenciáját Budapesten.
Results in English
We investigated collective phenomena in solids by multifrequency electron spin resonance spectroscopy. - Superconductors and parent magnetically ordered materials In the now „classic” CuO2 based perovskite superconductors we focused on systems on the borderline of antiferromagnetism and superconductivity. We investigated in detail the spatial distribution of magnetic spin density and charge density. - Magnetic and charge ordered states in manganite perovskites We investigated three structurally different systems for which the experimental verification of the theoretically predicted inhomogeneous charge distribution is the most interesting problem. - Electron delocalization in fullerene-based and carbon-based nanostructures We investigated in detail the C59N doped C60 system that may be regarded as a model system for fullerene semiconductors. In spite of its apparent simplicity it shows special electronic and magnetic features that were explained. We filled the carbon nanotubes with fullerene spin labels that enable the study of its electric properties. The work was accomplished in collaboration with several foreign laboratories. The ESR studies were performed on the multifrequency spectrometer built at the BUTE and the Bruker spectrometer at the Chemical Research Institute of the HAS. Results were published in well-known journals. We organized the closing conference of the SENTINEL European Network for high frequency ESR spectroscopy.
Full text http://real.mtak.hu/992/
Decision
Yes





 

List of publications

  
Jánossy A, Fehér T, Erb A: Diagonal Antiferromagnetic Easy Axis in Lightly hole doped Y1-xCaxBa2Cu3O6, Phys.Rev. Lett. 91: 177001, 2003
de Brion S, Storch G, Chouteau G, Jánossy A, Prellier W, Buzin ER: Phase Separation effects in charge - ordered Pr0.5Ca0.5MnO3 thin film, Eur. Phys. J. B 33: 413-418, 2003
Simon F, Atsarkin VA, Demidov VV, et al.: Electron spin resonance and relaxation studies of double-layered manganites, Phys. Rev. B 67 (22): 224433, 2003
Atsarkin VA, Demidov VV, Simon F, et al.: Electron spin relaxation in CMR manganites: absence of critical acceleration, J. Magn. Magn. Mater. 258: 256-258, 2003
Murányi F, Simon F, Fülöp F, Jánossy A: A longitudinally detected high-field ESR spectrometer for the measurement of spin-lattice relaxation times, J. Magn. Res. 167: 221-227, 2004
F. Simon, H. Kuzmany, H. Rauf, T. Pichler, J. Bernardi, H. Peterlik, L. Korecz, F. Fülöp, A. Jánossy: Low temperature fullerene encapsulation in single wall carbon nanotubes: synthesis of N@C60@SWCNT, Chem. Phys. Lett. 383: 362-367, 2004
Janossy A: Magnetic structure and hole localization in lightly doped CaYBaCuO, International Conference on Dynamic inhomogeneities in complex oxides, 2003
Jánossy A: Multifrequency ESR Study of the Magnetic Structure of Lightly Hole Doped YBCO, 15th ISMAR International Conference on Magnetic Resonance, Porto Vedra, Fl. USA 23-28 October, 2004, 2004
Janossy, A: Magnetic resonance in hole doped antiferromagnetic YBaCuO, Satellite conference of the ICM 2003, Pisa July 23-25 , 2003, 2003
Mihaly L, Talbayev D, Kiss LF, Zhou J, Feher T, Janossy A: Field-frequency mapping of the electron spin resonance in the paramagnetic and antiferromagnmetic states of LaMnO3, Phys. Rev. B 69: 024414, 2004
Simon F, Kuzmany H, Rauf H, Pichler T, Bernardi J, Peterlik H, Korecz L, Fülöp F, Jánossy A: Low temperature fullerene encapsulation in single wall carbon nanotubes: synthesis of N@C60@SWCNT, Chem. Phys. Lett. 383: 362-367, 2004
Muranyi F, Simon F, Fulop F, Janossy A: A longitudinally detected high-field ESR spectrometer for the measurement of spin-lattice relaxation times, J. Magn. Res. 167: 221-227, 2004
Gembus A, Simon F, Jánossy A, Kuzmany H, Dinse KP: Properties Of N@C60-Derived Peapods, Proceedings of the XIVth International Winterschool on Electronic Properties of Novel Materials Kirchberg 2004, AIP Conference Proceedings 723, 259, 2004
Janossy A: Electron spin resonance in high temperature superconductors and related materials, International Conference �Nanoscale Properties of Condensed Matter Probed by Resonance Phenomena� Kazan, Russia, 15-19 August, 2004, 2004
Murányi F, Simon F, Fülöp F, Jánossy A: Spin-lattice relaxation time of the superconductor MgB2 measured by a longitudinally detected ESR spectrometer, International Concerence on Low Energy Excitations in Solids, Kloster Blanz, DE, 18-23 July, 2004, 2004
Jánossy A: Electron Delocalization and Dimerization in Solid C59N-Doped C60 Fullerene, EU Network, \''SENTINEL\'' Workshop on Electron Paramagnetic Resonance at High Field and High Frequency: Tech. and Applications, Leiden, 10-12 May 2004, 2004
Quintavalle D, Jánossy A, Borondics F, Oszlányi G, Pekker S: Multifreqency ESR investigation of the fullerid polymer MgxC60 ( 0, EU Network, \''SENTINEL\'' Workshop on Electron Paramagnetic Resonance at High Field and High Frequency: Tech. and Applications, Leiden, 10-12 May 2004, 2004
Murányi F, Simon F, Fülöp F, Jánossy A: Spin relaxation in the superconductor MgB2, EU Network, \''SENTINEL\'' Workshop on Electron Paramagnetic Resonance at High Field and High Frequency: Tech. and Applications, Leiden, 10-12 May 2004, 2004
Nagy K, Erb A, Jánossy A: Gd ESR satellites of Ca first neighbors in Gd:CayY1-y Ba2Cu3O6, EU Network, \''SENTINEL\'' Workshop on Electron Paramagnetic Resonance at High Field and High Frequency: Tech. and Applications, Leiden, 10-12 May 2004, 2004
Holop C, Jánossy A, Kováts E, Klupp G, Pekker S: Electron Spin Resonance in Photo-oxidated Magnetic Fullerenes, EU Network, \SENTINEL Workshop on Electron Paramagnetic Resonance at High Field and High Frequency: Technology and Applications, Leiden, 10-12 May 2004, 2004
Náfrádi B, Jánossy, Kartovnik MV: High frequency ESR in the organic superconductors k-ET2Cu(NCS)2 and k-ET2Cu[N(CN)2]Br, EU Network, \''SENTINEL\'' Workshop on Electron Paramagnetic Resonance at High Field and High Frequency: Tech. and Applications, Leiden, 10-12 May 2004, 2004
Jánossy A: ESR search for stripes in Ca doped YBCO. Fluctuating Charge Order in HTSC, Workshop of Doping dependence of phase transitions and ordering phenomena in copper-oxygen superconductors\'' of the DFG, Garching, May 27/28, 2, 2004
Jánossy A: ESR search for stripes in lightly doped YBCO, University of Cambridge, UK, 1st November 2004, 2004
Rockenbauer A, Csányi G, Fülöp F, Garaj S, Korecz L, Lukács R, Simon F, Forró L, Pekker S, Jánossy A: Electron delocalization and dimerization in solid C59N doped C60 fullerene, Phys. Rev. Lett. 94(6): Art.No.0666603, 2005
Simon, F; Janossy, A; Feher, T; Muranyi, F; Garaj, S; Forro, L; Petrovic, C; Bud'ko, S; Ribeiro, RA; Canfield, PC:: Magnetic-field-induced density of states in MgB2: Spin susceptibility measured by conduction-electron spin resonance, Physical Review B, 72 (1): 012511, 2005
Simon F, Muranyi F: ESR spectrometer with a loop-gap resonator for cw and time resolved studies in a superconducting magnet, Journal of Magnetic Resonance, 173 (2): 288-295, 2005
Klupp G, Kamaras K, Oszlanyi G, Matus P, Kiss LF, Kovats E, Pekker S, Nemes NM, Brown C, Leao J, Quintavalle D, Janossy A: Nanosegregation in Na2C60, meghívott előadás, International Winterschool on Electronic Properties of Novel Materials 2005, Austria, Kirchberg, 12.- 19.3.2005, 2005
Rockenbauer, A; Csanyi, G; Fulop, F; Garaj, S; Korecz, L; Lukacs, R; Simon, F; Forro, L; Pekker, S; Janossy, A: Electron delocalization and dimerization in solid C59N doped C-60 fullerene, Proceedings of the XVth International Winterschool on Electronic, Properties of Novel Materials Kirchberg, 2005
Lenz, K; Wende, H; Kuch, W; Baberschke, K; Nagy, K; Janossy, A: Two-magnon scattering and viscous Gilbert damping in ultrathin ferromagnets, Physical Rewiev B, 73 (14): Art. No. 144424, 2006
Janossy, A: ESR search for stripes in Ca doped YBCO, Workshop of the Research Unit 538 ''Doping dependence of phase transitions and ordering phenomena in copper-oxygen superconductors'' of the DFG (Germany), 2005
Janossy, A: Search for stripes in lightly hole doped antiferromagnetic YBCO, International ICAM Workshop NMR/EPR of Correlated Electron Superconductors, 2005




 

Events of the project

  
2010-04-12 13:23:19
Kutatóhely váltás
A kutatás helye megváltozott. Korábbi kutatóhely: Kísérleti Fizika Tanszék (Budapesti Műszaki és Gazdaságtudományi Egyetem), Új kutatóhely: Fizika Tanszék (Budapesti Műszaki és Gazdaságtudományi Egyetem).



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