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Achieving the world record for X-ray Spectroscopy Experiment in Ultrahigh Magnetic FieldsJul. 28, 2009A joint research group has established the world record of X-ray Magnetic Circular Dichroism (XMCD) Spectroscopy. It provides element and orbital-selective magnetizations up to 40 tesla that is as high as 1 million times of terrestrial magnetism. The group consists of Professor Hiroyuki Nojiri at Institute for Materials Research, Tohoku University, Associate Professor Yasuhiro Matsuda at Institute for Solid State Physics, University of Tokyo, Dr. Toshiya Inami at Japan Atomic Energy Agency (JAEA), Dr. Motohiro Suzuki at The Japan Synchrotron Radiation Research Institute (JASRI), and Associate Professor Akihiro Mitsuda at Graduate School of Sciences, Kyushu University. The research results came from a combination of high-intensity X-ray of SPring-8 and newly developed strong mini-pulsed magnet. By using this system, experiments can be conducted in any places promptly without changing of existing spectrometer and without installing new infrastructures needed for conventional magnetic field generators. The Tohoku University method has been introduced in the top class quantum beam facilities over the world. The most important scientific breakthrough is the extension of XMCD applications for �any magnets�. It is the great advantage of the present method, because normal XMCD can be applied only for ferromagnetic compounds, which is obtained only by chances. In extremely strong magnetic field of 40 T, most of material can be magnetized and thus XMCD signal is easily obtained. As a result, XMCD can be used to investigate various magnetic materials including magnetic memory material. A systematic study becomes possible which is essential to design materials efficiently. In this study, the research group applied the XMCD method to intermetallic materials including europium as one of rare-earth element. Europium has been known to show odd properties that show fluctuation between magnetic and non-magnetic states caused by the quantum mechanical valence mixing. It had been difficult to investigate these two states precisely in high magnetic fields. The group has found directly that magnetic field responses of those two states are completely different for the first time. It shows that the newly developed XMCD method is powerful for investigating electronics states of materials in element and orbital selective manner. It would contribute to designing and development of new magnetic materials for magnetic memory or sensor. The research results have been published in �Physical Review Letters� (a scientific journal issued by American Physical Society) on July 28, 2009. The paper�s title is _X-ray Magnetic Circular Dichroism of Valence Fluctuating State in Eu at HighMagnetic Fields._ |
