Second Seeheim Conference on Magnetism (SCM2004) Seeheim, Germany, 27 June–1 July 2004

phys. stat. sol. (a) 201, No. 12, 2611–2614 (2004) / DOI 10.1002/pssa.200406882

© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Conference Report

Second Seeheim Conference on Magnetism (SCM2004) Seeheim, Germany, 27 June–1 July 2004

Srikanth Hariharan*

Department of Physics, University of South Florida, Tampa, FL 33620, USA Conference Reports are meant to offer an authoritative view on a recently held scientific meeting rather than a comprehensive list of the conference presentations. Authors are invited to describe what they feel were the most interesting contributions.

The full Proceedings of the Second Seeheim Conference on Magnetism (SCM2004) will appear in phys. stat. sol. (c) in autumn 2004. Conference papers will also be published in phys. stat. sol. (a).


Magnetism and magnetic materials have rapidly advanced in recent years with the advent of nanostruc-tured materials exhibiting fascinating properties and the discovery of various spin-dependent phenomena. Being a popular branch of Solid State/Condensed Matter research, international conferences and work-shops in this field have always attracted researchers from far and wide to congregate and enthusiastically discuss their work. In this respect, the Second Seeheim Conference on Magnetism (SCM2004) was no exception and lived up to the expectation of being an excellent forum for discussing current progress in topical areas of magnetism. SCM2004 was the second in a series of conferences organized by a consortium of Universities in Germany led by Darmstadt University of Technology and the University of Ulm. It was supported by the Deutsche Forschungsgemeinschaft and the Forschungszentrum Karlsruhe. The conference organizers could not have done better in choosing the idyllic location of the Lufthansa Training Center Seeheim nestled at the edge of Odenwald forest in Central Germany. SCM2004 was well attended with 182 participants from 35 countries. The number of countries repre-sented was particularly impressive and gave a truly international dimension to this meeting. Under-standably, Germany was the most represented with 35 participants followed by Korea (25), Japan (13), Poland (9), Turkey (8), France (7), Taiwan (7), Italy (6), Hungary (6), Brazil (5), Czech Republic (5), Ukraine (5), Greece (4), India (4), Netherlands (4), Spain (4), USA (4), Belgium (3), Israel (3), Iran (3), Romania (3), Slovakia (3), UK (3), Switzerland (2), Denmark (2), Slovenia (2), Australia (1), China (1), Canada (1), Ireland (1), Portugal (1), Singapore (1), Sweden (1). These days with the size of conferences getting bigger and parallel sessions the norm, SCM2004 was a welcome change as it offered a busy but tightly scheduled single session program over 4 days featuring 23 invited talks, 30 contributed oral and 204 poster presentations. A total of 148 manuscripts were sub-mitted for publication in the conference proceedings. The conference also attracted a few exhibitors with booths from Wiley-VCH and NT-MDT – a company that specializes in various scanning probe instru-ments.

* e-mail: [email protected], Phone: +1 813-974-2467, Fax: +1 813-974-5813

2612 S. Hariharan: Second Seeheim Conference on Magnetism (SCM2004)


The focus was on nanostructured materials, surfaces, interfaces and nanoparticles and latest develop-ments in these areas were actively discussed. There was a definite emphasis by a majority of presenters on magnetization dynamics as probed by Mössbauer spectroscopy, relaxation and spin-glass phenomena, and transport in low dimensional materials. After arrival on 27 June and registration for most delegates, the meeting began on 28 June (Monday) morning with a brief welcome address by Conference Chair Mohammad Ghafari from Darmstadt. He mentioned that a measure of success of the first SCM conference held in 2001 was evident in the fact that papers published in the Proceedings in a special issue of physica status solidi (a) [1] were downloaded over 14000 times. The morning session had 4 invited and 7 contributed talks with focus mainly on thin films and multilayer structures. The session opened with an invited talk by Wigen (Ohio State University). Wigen gave a review of the promising technique of Magnetic Resonance Force Mi-croscopy (MRFM) that is useful as a non-invasive probe of the dynamic magnetic properties on a micro-scopic scale. In the FMR mode, this technique also offers the possibility of observing magnetostatic modes and example studies on YIG samples were presented. Wigen also credited the team of Dan Rugar et al. from IBM Almaden for pulling off the impressive feat of demonstrating single spin detection using MRFM. Can magnetoresistance (MR) measurements provide information about the magnetization reversal process? In an invited talk, Dumpich (University of Duisburg) provided insights into how this is indeed possible from careful low temperature resistivity and MR measurements on e-beam lithographically patterned Co nanowires. A key result was the absence of weak localization effects and dominance of electron–electron interaction effects in the transport properties. Baggio-Saitovitch (CBPF, Brazil) talked about magnetic properties of dilute alloys of Fe embedded in non-magnetic metals like Ag, Cd prepared by vapor quenching and presented in-situ Mössbauer spectroscopy results across the blocking-superparamagnetic transition. Szymczak (Polish Academy of Sciences, Warsaw) presented an overview of the origin and importance of magnetostriction in thin films of manganites and cobaltites. The strong magnetoelastic coupling is associated with orbital degeneracy of Mn3+ and Co3+ ions in these materials. Magnetoelastic stress measurements were done using a capacitance cantilever technique. The morning session ended with a presentation on multiferroic materials by Eerenstein (Cambridge University, UK).

Conference Chairman Mohammad Ghafari giving the opening remarks

phys. stat. sol. (a) 201, No. 12 (2004) / www.pss-a.com 2613


These are interesting materials and mostly oxides with perovskite structure with coexistence of both ferroelectric and ferromagnetic ordering with unusual coupling between them. The Monday afternoon session was entirely devoted to posters and there were a large number of them. Attendees could be seen milling around the designated poster areas and having animated conversations with the presenters. In my opinion, poster sessions are rather important at any meeting and afford the chance for having the best interactive discussions on a one-to-one basis. The organizers could have planned this session better. Instead of having all the posters displayed in one session, it could have been divided into categories and spread over two or three days. However, it is understandable that the organiz-ers may have been overwhelmed by the number of posters and did the best they could. I would point this out as an area where there is scope for improvement in future SCM conferences. The poster presentations covered the entire gamut of topical areas in magnetism ranging from basic phenomena to applications. A large number of posters focused on ferrites, manganites and good number were on microstructure and physical properties of nanoparticles and thin films. 29 June (Tuesday) was the most hectic day of the conference with 9 invited and 13 contributed talks spanning the whole day. In the morning session, Koch (Paul-Drude Institute, Berlin) gave an interesting talk on using MnAs/GaAs sandwich layers to perform basic logic operations such as OR, AND etc. This is achieved by individual interrogation of in-plane and out-of-plane magnetization components using a sensitive cantilever beam magnetometer. The hierarchy of reconfigurable logic with single magnetoresis-tive elements was quite fascinating. Gajbhiye (Indian Institute of Technology, Kanpur) presented various chemical methods to synthesize Fe–N nanoparticles and discussed their electronic and magnetic proper-ties. Lee (Inha University, Korea) presented theoretical calculations of electronic carbon nanotubes (CNT) functionalized by filling them with magnetic transition metals Fe, Co and Ni. A striking predic-tion was the large spin polarization (> 90%) in these systems. A highlight of Tuesday morning and perhaps the entire conference was the insightful invited talk given by Mørup (Technical University of Denmark). Mørup outlined a simple spin wave theory to ac-count for the anomalous temperature dependence of magnetization reported by experimental groups in antiferromagnetic nanoparticles. The increase in magnetic moment with increasing temperature observed in these systems is due to thermo-induced net magnetization caused by difference in precession angles of the two sublattices in the antiferromagnet. This means that even with all spins compensated, antiferro-magnetism is non-existent in nanoparticles! This simple and elegant theory [2] resolves a puzzle and has recently been highlighted in the Physics Update section of the July 2004 issue of Physics Today maga-zine. Other invited speakers on Tuesday included Prandolini (Hahn–Meitner-Institute, Berlin) who dis-cussed magnetic properties of impurities at ferromagnetic surfaces and interfaces using Perturbed Angu-lar Correlation (PAC) spectroscopy, and Campbell (The University of New South Wales, ADFA, Austra-lia) who presented extensive investigations of rare-earth intermetallic compounds containing Yb and Eu. In the afternoon session on Tuesday, Hütten (University of Bielefeld, Germany) made a case for Co2MnSi Heusler alloys as promising materials for magnetic electrodes in tunnel junctions. What makes Co2MnSi so special? It has a high Curie temperature (Tc = 985 K) and predicted to be 100% spin polar-ized. It has been a challenge to integrate Heusler alloys as junction electrodes and the results presented in this talk looked promising as the low temperature tunneling magnetoresistance (TMR) was larger than that of Ni–Fe and Co–Fe electrodes. Berkov (INNOVENT, Jena, Germany) discussed a software pack-age developed to undertake a wide range of simulations of magnetization dynamics. Specific examples from the literature were considered and numerical simulations were presented. Pogorelov (University of Porto, Portugal) presented a rigorous theoretical model to explain the peculiar 4th order anisotropy ob-served in FMR studies on planar lattices of Permalloy (Py) microdots. An invited talk by Binns (Univer-sity of Leicester, UK) featured magnetism and dynamics in Fe nano-clusters deposited on Si substrates using a UHV cluster source. Enhanced magnetic moment (2.3 µB) was observed in free clusters (~2 nm) over that of the bulk (2 µB). X-ray magnetic circular dichroism was done to analyze the spin and orbital contributions to the magnetic moment. Similar experiments on Co-coated Fe clusters were also pre-sented. The last presentation was from Elmers (Johannes-Gutenberg University, Mainz) on how fast magnetization processes can be observed in stroboscopic pump–probe experiments using X-ray photo-emission electron emission microscopy (X-PEEM) with picosecond resolution.

2614 S. Hariharan: Second Seeheim Conference on Magnetism (SCM2004)


The third day of the conference (30 June, Wednesday) was limited to the morning session only as a sightseeing trip was arranged for the participants in the afternoon. There were 6 invited and 4 contributed talks. Kleemann (University of Duisburg) started off proceedings with a comprehensive summary of the rich phase diagram of soft ferromagnetic Co80Fe20 nanoparticles embedded as a discontinuous multilayer in an Al2O3 matrix. Instead of individual blocking, the system favors generic freezing processes consis-tent with a superspin glass behavior. With increasing layer thickness, superferromagnetism was ob-served. Kleemann discussed the physics of these various phases and also presented polarized neutron reflectometry results. Yao (Academica Sinica, Taiwan) showed some interesting results on current-driven magnetization dynamics in patterned U and S shaped Ni–Fe structures. Magnetic force micros-copy (MFM) quantitatively support the current-driven switching processes observed in these structures. Weismüller (Forschungszentrum Karlsruhe) gave an overview of how magnetic small-angle neutron scattering can be used to probe spin disorder at the nanoscale with excellent spatial resolution. The ses-sion had several other talks including one from Wilhelm (EPSRF, Grenoble) on the versatility of X-ray magnetic circular dichroism (XMCD) in studying magnetism in multilayers and films. Bogdanov (Leib-niz Institute, Dresden) wrapped up proceedings for the day with a presentation of a theoretical model that is effective in describing the spin-flop transition and numerous magnetic reorientation phenomena ob-served in antiferromagnetic superlattices. On the last day of the conference (1 July, Thursday), there were 4 invited and 6 contributed talks cov-ering a variety of topics from molecular magnetism to micromagnetic simulations. Gütlich (Johannes-Gutenberg-University, Mainz) gave a very interesting invited talk on pressure effect studies in molecular magnetism. Although the topic was somewhat different from the mainstream focus of this conference, Gütlich’s detailed and pedagogic presentation was quite appealing. Using several examples, he explained how chemical pressure by doping induces spin transitions and novel cooperative magnetic behavior in molecular magnets. Shinjo (IIAS, Kyoto) presented MFM studies of switching, vortex core magnetiza-tion and domain wall displacement in magnetic dots and wires with visually appealing slides. Nasu (Osaka University) discussed high-pressure Mössbauer spectroscopy of the Fe–N system. Following the 57Fe Mossbauer spectrum, the six-line magnetic hyperfine interaction collapses into two paramagnetic components under application of 20 GPa pressure. The last session of the conference also featured pres-entations from Trohidou (NCSR, Demokritos) on Monte Carlo simulation of Co clusters on Au surfaces and Asti (University of Parma) who discussed measurements of anisotropy fields using singular point detection (SPD) in M-type hexaferrites. The closing remarks were given by Wigen (Ohio State Univer-sity) in his inimitable style. In summary, SCM2004 was a well organized conference that brought together a sizeable number of international researchers. Topical areas in magnetism were covered and the conference venue and ar-rangements reminded me of one of those Gordon Research Conferences. The organizers are to be com-mended for their efforts and I am already looking forwarded to the next conference in the SCM series. The full Proceedings of SCM2004 will appear in physica status solidi (c) in autumn 2004. Conference papers will also be published in a forthcoming issue of physica status solidi (a).

References

[1] Proceedings of the First Seeheim Conference on Magnetism (SCM2001), phys. stat. sol. (a) 189, Nos. 2, 3 (2002).

[2] S. Mørup and C. Frandsen, Phys. Rev. Lett. 92, 217201 (2004).

Second Seeheim Conference on Magnetism (SCM2004) Seeheim, Germany, 27 June–1 July 2004

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Transcript of Second Seeheim Conference on Magnetism (SCM2004) Seeheim, Germany, 27 June–1 July 2004