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Forschungszentrum Jülich Institut für Festkörperforschung
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The Institut für Mikrostrukturforschung (Institute for Microstructure Research) is working in a number of fields selected with an emphasis on the atomistic and microstructural understanding of materials properties and the possibility to contribute to the development of technology. In some of these fields the competence spans the whole range from basic research to technical devices. In others access to interesting materials and problems is provided by qualified collaborations. Besides this general-physics and technology part of the institute there is a second part of special competence. This is structure research by means of modern transmission electron microscopy and scanning tunneling microscopy and the development of advanced investigation methods for these. This work is carried out within the Jülich Center for High-Resolution Electron Microscopy operated by the institute. Research Fields Equipment The institute operates sputtering deposition machines, some of them with three-target facilities, which were developed and built in the institute for the high-quality deposition of ceramic superconductor thin films and heterostructures. Copies of these machines could be sold successfully to laboratories around the world. For SQUID reference studies we have a magnetically shielded room. For device production local clean room, structuring and packaging facilities are available. The institute operates the Jülich Center for High-Resolution Electron Microscopy with two 400 kV JEOL machines of the type 4000 EX/FX, a JEOL 2000 EX, a PHILIPS CM20 FEG, the spherical-aberration corrected PHILIPS CM200 FEG and a JEOL 840A scanning microscope. The new DFG-funded SATEM instrument, an aberration corrected sub-Ångstrom TEM produced by ZEISS-LEO will be installed in autumn 2003. Our instruments for scanning tunneling microscopy: Two microscopes with in-situ cleaving facilities and ex-situ heating up to 750 °C and an in-situ heating STM (Omicron). For the work on alloy plasticity a Zwick mechanical testing system is available. Special results and developments in 2002 The YBa2Cu3O7 dc-SQUID sensors, developed and produced in our institute show the world’s highest sensitivity and have already found many applications around the world. Distributed by TTB (FZJ) and Tristan Technologies Inc.(San Diego, California) our SQUIDs are used in commercial measurement systems. The market demands represent challenges to science and technology, and our work in this field will be continued as long as we can derive good science from it. Submicrometer wide high-Tc bicrystal Josephson junctions with a normal state resistance of about 10 W
and a critical current density of about 2 ´
104 A/cm2 (IcRn product of about 400 µV) at 77.4 K were developed. We have significantly improved the noise properties of dc flip-chip magnetometers with submicrometer wide bicrystal junctions. We demonstrated a modulation voltage Vpp up to 80 µV compared to about 30 µV for the magnetometers with 1.5 µm junctions. The noise of the magnetometers with electronics was about 6 fT/Ö
Hz at frequencies above 100 Hz and about 20 fT/Ö
Hz at 1 Hz. An axial first order gradiometer system, gradient resolution of about 1 fT/cmÖ
Hz at 77.4 K, was developed for biomagnetic measurements. It was successfully used in a BMBF project on biomagnetism and application in clinical environment. For application in semiconductor industry a non-contact measurement system for the distribution of the photo-induced magnetic field from p-n junctions in devices using a laser SQUID microscope and our SQUID sensors was developed successfully in Japan. In the framework of our collaboration with the Institute of Radio Engineering, Moscow, we pursue our development of Hilbert-spectroscopy for the far-infra red range. For this we have measured the critical current density (jC) distribution of [001]-tilt YBa2Cu3O7 bicrystal Josephson junctions by means of the laser probing technique. The topography of the grain boundaries for the junctions with maximum and minimum jC was studied by AFM and high-resolution TEM. We could show: The boundaries with high jC consist mainly of symmetrical while those with low jC consist of asymmetrical facets. In junctions optimized on this basis we investigated the broadband spectral range from GHz to THz frequencies. The low-frequency limit of the Josephson effect could be shown to be due to the finite linewidth of the Josephson oscillations while the high-frequency limit is determined by interaction of Josephson oscillations with strong optical phonons in YBa2Cu3O7. A Hilbert spectrometer for operation with pulsed far-infrared radiation has been developed and characterized. It employs a [001]-tilt YBa2Cu3O7-x bicrystal junction in an optical cryostat. The spectral range of the spectrometer extends from 30 to 1200 GHz at the junction temperature of 78 K and can be shifted to the higher frequencies by lowering the junction temperature. We have demonstrated earlier that Hilbert-spectroscopy has great potential for beam diagnostics in high-energy electron accelerators. New applications are in the testing of ultra-fast electronic devices. A scanning SQUID microscope for the investigation of room temperature samples has been built and successfully tested (collaboration with ZEL). Its resolution surpasses that of commercial systems. The application of this type of microscope for information technology especially in the field of failure analysis of semiconductor devices, e.g. the non-destructive detection of package- or chip level shorts of micro circuits, or the investigation of magnetic storage devices looks promising. Setting a benchmark in quantitative diffraction contrast imaging, the gas pressure of helium-filled nanocracks formed upon implantation and annealing of silicon was measured for individual cavities at high precision. This parameter, which plays an import role in the plastic relaxation of implanted semiconductors, has been directly measured for the first time. Our laboratory is still the only one operating a spherical-aberration corrected TEM. The technique of multipole-aberration corrector systems pioneered by the institute together with CEOS, Heidelberg, and TU Darmstadt has started a new era in transmission electron microscopy. All TEM companies, ZEISS-LEO Oberkochen, FEI (USA, formerly Philips Electron Optics), JEOL and Hitachi (Japan) are working on new microscope designs containing correctors. Our institute receives a large number of international visitors every year who are interested in the new technology. On the other hand, the very high number of invited keynote lectures on international conferences underlines the pioneering role and high reputation of our group in this field. The international electron optics community reacted enthusiastically to our discovery that adjusting small negative spherical-aberration values (by overcompensation of the original instruments aberration) revolutionizes atomic-resolution imaging. Negative spherical aberration imaging allows, e.g., to image oxygen in perovskite ceramics (SCIENCE, in press) where the local oxygen content sensitively controls the electronic properties. The alloy physics group has successfully started an extended research program in the new field of complex alloy phases (SCAP). This concerns intermetallics with giant unit cells containing hundreds to thousands of atoms on which essentially nothing is known with respect to physical properties. Procedures for the growth of centimeter-sized high-quality single crystals of a number of such alloys were developed. These constitute the first reliable samples for physical property measurements of this novel class of materials. A special Symposium was organized by us and Prof. Trebin, University of Stuttgart, at the DPG Frühjahrstagung 2002 in Regensburg. This field was selected (spring 2002) by the French and Germany ministers of science as a field of preference for French-Germany science collaboration in materials science. Structurally complex alloy phases is also the topic of a European Network of Excellence "CMA" (Coordinators: Profs. K. Urban, Jülich, J.-M. Dubois, Nancy, L. Schlapbach, Fribourg, J. Hafner, Wien) to be applied for in the 6th Framework Program of the EC. The Chinese-German research program on Modern Metallic Materials Design organized on behalf of the DFG and the NSFC by Profs. Herlach, Köln, and Urban, Jülich, has been granted by the DFG Senate in September 2002. The work of our group together with the Institute of Physics CAS and Wuhan University on SCAP has started in December 2002. In recent years great efforts went into joint doctor student programs with foreign universities. Formal contracts were signed with the Russian Academy of Sciences, the University of Kiev, the Tsinghua University and the Institute of Physics, Beijing, the Dalian University and Wuhan University, China. In the framework of this special program the doctor students are working up to three years in Jülich on a grant supervised by the Jülich Doktorandenausschuß, but they will pass their examina in their home university. A number of doctor students from Moscow Institute of Science and Technology, of Dalian University and of Wuhan University where Prof. Urban holds a professorship are working at Jülich. Students from the Institute of Physics will follow during this year. It was a great gain and honor for the institute to be the host for extended stays of the Humboldt prizewinners Prof. Frans Spaepen, Harvard University, Cambridge, Mass., and Prof. Berry Carter, University of Minnesota, Minneapolis. Prof. Dr. Knut Urban Personnel 2002 / 2003 and areas of activity Dr.
Y. Divin
Hilbert-spectroscopy
2342004
Dr.
Ph. Ebert
Scanning
tunneling microscopy of semiconductors and quasicrystals
2310204
Dr.
M. Faley
High-Tc-Superconductor
SQUIDs, Multilayer structures, SQUID-Microscopy
2342004
Dr.
M. Feuerbacher
Plasticity
of quasicrystals
2310204
Dr.
B. Grushko
Crystal
growth, phase diagrams of alloys
2310204
Dr.
C.L. Jia
Characterization
of superconductors, diamond and electroceramic films by high-resolution
electron microsopy
2342004
Dr.
M. Lentzen
Reconstruction
techniques in high-resolution electron microscopy, Cs-corrected
transmission electron microscopy for imaging of interfaces
in semiconductors and of superconducting materials
2310204 Dr.
M. Luysberg Transmission
electron microscopy of semiconductor heterostructures, low-temperature
GaAs and microcrystalline silicon
2342004
Dr.
U. Poppe
Superconductivity,
tunneling spectroscopy, High-Tc superconductor
thin films and multilayers, SQUID-Microscopy
2342004
Dr.
A. Thust
Reconstruction
techniques in high-resolution electron microscopy, Cs-corrected
transmission electron microscopy for imaging of interfaces
in semiconductors, electron microscopy of superconducting
materials
2342004
Prof.
Dr. K. Urban
Head
of Institute
2310204
Publications in journals Baier,F.*; Müller,M.A.*; Sprengel,W.*; Grushko,B.; Strertzel,W.*;
Assmus,W.*; Schäfer,H.E.* Bert,F.*; Belessa,G.*; Grushko,B. C. Cao,L. X.*; Kremer,R.K.*; Qin,Y.L.; Brötz,J.*; Liu,J. S.*;
Zegenhagen,J.* Cao,L. X.*; Qin,Y. L.; Deac,A.*; Snigireva,I.*; Zegenhagen,J.* Chen,J. H.; Jia,C.L.; Urban,K.; Chen,C. L.* Divin,Y. Y.; Volkov,O. Y.*; Laytti,M.; Shirotov,V. V.; Pavlovskii,V.
V.*; Poppe,U.; Shadrin,P. M.; Urban,K. Divin,Y.Y.; Poppe,U.; Jia,C.L.; Shadrin,P.M.*; Urban,K. Divin,Y.Y.; Volkov,O.Y.*; Liatti,M.*; Shirotov,V.V.*; Pavlovskii,V.V.*;
Poppe,U.; Shadrin,P.M.*; Urban,K. Dolinsek,J.*; Apih,T.*; Jeglic,P.*; Feuerbacher,M.; Calvo-Dahlborg,M.*;
Dubois,J.M.* Döblinger,M.*; Wittmann,R.; Gerthsen,D.; Grushko,B. Ebert,P. Faley,M. I.; Poppe,U.; Urban,K.; Paulson,D. N.*; Starr,T. N.*;
Fagaly,R. L.* Faley,M.I.; Poppe,U.; Urban,K.; Paulson,D.N.*; Fagaly,R.L.* Faley,M.I.; Poppe,U.; Urban,K.; Slobodchikov,V.Y.*; Maslennikov,Y.
V.*; Gapelyuk,A.*; Sawitzki,B.*; Schirdewan,A.* Franke,K. H.*; Sharma,H.R.*; Theis,W.*; Gille,P.*; Ebert,P.; Rieder,H.* Grushko,B. C.; Döblinger,M.*; Wittmann,R.*; Holland-Moritz,D.* Grushko,B.; Mi,S.; Highfield,J.G.* He,J.Q.; Regnery,S.*; Jia,C.L.; Qin,Y.L.*; Fetsilis,F.*; Erhardt,P.;
Waser,R.; Urban,K.; Wang,R.H.* Heggen,M.; Feuerbacher,M.; Lange,T.; Urban,K. Herzog,H.-J.*; Hackbarth,T.*; Seiler,U.*; König,U.*; Holländer,B.;
Mantl,S. Houben,L.; Scholten,C.; Luysberg,M.; Vetterl,O.; Finger,F.; Carius,R. Jia,C.L.; Rodriguez - Contreras,J.*; Poppe,U.; Kohlstedt,H.*; Waser,R.;
Urban,K. Jiang,C.S.*; Yu,H.*; Shih,C.K.*; Ebert,P. Jiang,X.*; Jia,C. L. Jiang,X.*; Jia,C.L.; Szyszka,B.* Jäger,N.D.; Ebert,P.; Urban,K.; Krause-Rehberg,R.*; Weber,E.R.* Jäger,N.D.; Urban,K.; Weber,E.R.*; Ebert,P. Kluge,F.; Yurechko,M.; Urban,K.; Ebert,P. Krause,H.J.*; Wolf,W.*; Glaas,W.*; Zimmermann,E.*; Faley,M.I.;
Sawade,G.*; Mattheus,R.*; Neudert,G.*; Gampe,U.*; Krieger,J.* Lentzen,M.; Jahnen,B.; Jia,C.L.; Thust,A.; Tillmann,K.; Urban,K. Luysberg,M.; Kirch,D.; Trinkaus,H.; Holländer,B.; Lenk,St.;
Mantl,S.; Herzog,H.-J.*; Hackbarth,T.*; Fichtner,P.F.P.* Luysberg,M.; Kirch,D.; Trinkaus,H.; Holländer,B.; Lenk,St.;
Mantl,S.; Herzog,H.-J.*; Hackbarth,T.*; Fichtner,P.F.P.* Messerschmidt,U.*; Petukhov,B.V.*; Bartsch,M.*; Dietzsch,Ch.*;
Geyer,B.*; Häussler,L.*; Ledig,L.*; Feuerbacher,M.; Schall,P.;
Urban,K. Qin,Y. L.; Jia,C. L.; Urban,K.; Liedtke,R.; Waser,R. Qin,Y.L.; Jia,C.L.; Urban,K.; Liedtke,R.*; Waser,R. Shadrin,P. M.; Jia,C. L.; Divin,Y. Y. Shadrin,P.*; Jia,C.L.; Divin,Y. Shirotov,V. V.; Divin,Y. Y.; Urban,K. Shirotov,V.V.*; Divin,Y.Y.; Urban,K. Tillmann,K.; Luysberg,M.; Specht,P.*; Weber,E.R.* Urban,K.; Feuerbacher,M.; Klein,H. Weidner,E.*; Lei,J. L.; Frey,F.*; Wang,R.*; Grushko,B. Wu,J.S.; Jia,C.L.; Urban,K.; Hao,J. H.*; Xi,X. X.* Yang,W.*; Feuerbacher,M.; Urban,K. Yao,Yu.*; Ebert,P.; Li,M.*; Zhang,Zh.*; Wang,E.G.* Yu,H.*; Jiang,C.S.*; Ebert,P.; Shilh,C.K.* Yu,H.*; Jiang,C.S.*; Ebert,P.; Wang,X.D.*; White,J.M.*; Niu,Q.*;
Zhang,Zh.*; Shih,C.K.* Yurechko,M.; Grushko,B.; Velikanova,T.*; Urban,K.
Faley,M.I.; Poppe,U.; Urban,K.; Slobodchikov,V.Y.*; Maslennikov,Y.
V.*; Gapelyuk,A.*; Sawitzki,B.*; Schirdewan,A.* Jäger,N.D.; Urban,K.; Weber,E.R.*; Ebert,P. Klein,S.; Finger,F.; Carius,R.; Rech,B.; Luysberg,M.; Stutzmann,M.* Luysberg,M.; Kirch,D.; Trinkaus,H.; Holländer,B.; Lenk,St.;
Mantl,S.; Herzog,H.-J.*; Hackbarth,T.*; Fichtner,P.F.P.* Tillmann,K.; Luysberg,M.; Specht,P.*; Weber,E.R.* Urban,K.; Feuerbacher,M.; Wollgarten,M. Wollgarten,M.; Franz,V.; Feuerbacher,M.; Urban,K. Yurechko,M.V.; Velikanova,T.Ya.*; Grushko,B. C.
Baier,F.*; Müller,M.A.*; Sprengel,W.*; Grushko,B.; Strertzel,W.*;
Assmus,W.*; Schäfer,H.E.* Divin,Y.Y.; Volkov,O.Y.*; Liatti,M. V.; Gubankov,V. N.* Ebert,P. Ebert,P. Ebert,P.; Domke,C.; Urban,K. Feuerbacher,M. Feuerbacher,M. Franke,K. J.*; Sharma,H.R.*; Theis,W.*; Gille,P.*; Ebert,P.; Rieder,K.H.* Houben,L.; Luysberg,M.; Brammer,T.* Hüging,N.; Tillmann,K.; Trinkaus,H.; Urban,K.; Holländer,B.;
Mantl,S.; Fichtner,P.*; Luysberg,M. Jahnen,B.; Luysberg,M. Jia,C.L. Jäger,N.-D.; Urban,K.; Weber,E.R.*; Ebert,P. Jäger,N.D.; Urban,K.; Weber,E.R.*; Ebert,P. Jäger,N.D.; Urban,K.; Weber,E.R.*; Ebert,P. Klein,S.; Finger,F.; Carius,R.; Rech,B.; Stutzmann,M.* Luysberg,M.; Hüging,N.; Tillmann,K.; Trinkaus,H.; Urban,K.;
Holländer,B.; Mantl,S.; Fichtner,P.* Luysberg,M.; Kirch,D.; Holländer,B.; Mantl,S.; Lenk,St.; Trinkaus,H.;
Hackbarth,Th.*; Herzog,H. J.*; Fichtner,P.* Luysberg,M.; Kirch,D.; Holländer,D.; Mantl,S.; Lenk,St.; Trinkaus,H.;
Hackbarth,Th.*; Herzog,H.-J.*; Fichtner,P.* Theis,W.*; Franke,J. K.*; Kury,P.*; Horn-von-Hoegen,M.*; Gille,P.*;
Ebert,P.; Rieder,K.H.* Tillmann,K.; Luysberg,M.; Specht,P.*; Cich,M.*; Weber,E.R.* Tillmann,K.; Luysberg,M.; Specht,P.*; Weber,E.R.* Tillmann,K.; Luysberg,M.; Specht,P.*; Weber,E.R.*
Ebert,P. Ebert,P.; Kreibig,U.*; Mantl,S.; Michely,Th.*; Urban,K.; von Plessen,G.*;
Wuttig,M.* Luysberg,M.
Faley,M.I.; Poppe,U.; Urban,K.; Slobodchikov,V.Y.*; Maslennikov,Y.
V.*; Gapelyuk,A.*; Sawitzki,B.*; Schirdewan,A.* Jäger,N.-D.; Urban,K.; Weber,E.R.*; Ebert,P. Semmler,U.; Ebert,P.; Urban,K. Shirotov,V.*; Divin,Y.; Poppe,U.; Larue,H.*; Zimmermann,E.*; Ahmet,A.*;
Halling,H.*; Urban,K.
Faley M.I.; Poppe U., Jia C.L.; Zimmermann E.1; Poppe U.2; ; Faley M.2; Halling H.1 Zimmermann E.1; Glaas W.1; Halling H.1; Faley M.2; Soltner H.3 |
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