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Intellectual Merit

Bonding and Magnetic Exchange in the Metal-TCNE Magnet Family Konstantin I. Pokhodnya, North Dakota State University Fargo, DMR 1005882. Intellectual Merit

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Intellectual Merit

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  1. Bonding and Magnetic Exchange in the Metal-TCNE Magnet FamilyKonstantin I. Pokhodnya, North Dakota State University Fargo, DMR 1005882 Intellectual Merit This study addresses the subject of magnetic interaction (or exchange) between electron spins (i.e. magnetic moments) in molecule-based magnets, and how the interaction is facilitated by chemical bonding that holds these solids together. M[TCNE] (M = 3d transition metal, TCNE = tetracyanoethylene) magnets are an important class of solids with examples of very high magnetic ordering temperature, Tc (below which the material is magnetic) in excess of 400 K, allowing for realization of some microelectronic applications. By varying the metal ion, anion size, and pressure we were able to systematically alter Tc thus allowing for a relationship between bonding and magnetic exchange to be established. A deeper understanding of magnetic exchange and how to control Tc is an important advance not only in the magnetism research but also with regard to application of molecule-based magnetic solids as injectors of spin-polarized carriers. Further, application of a novel spectroscopy technique, i.e. ultraviolet-visible magnetic circular dichroism, provided an important insight into the exchange problem that other techniques for the prior twenty years had failed to see. Fe(TCNE)FeCl4 Mn(TCNE)SbF6 The Raman response of Mn(TCNE)SbF6 and similar Fe(TCNE)FeCl4 layered magnets under pressure has shown that the evolution of the ag C=C stretching mode frequency correlates well with the magnetic exchange and Tc variations of these materials.

  2. Bonding and Magnetic Exchange in the Metal-TCNE Magnet FamilyKonstantin I. Pokhodnya, North Dakota State University Fargo, DMR 1005882 On August 26th 2011, a community research fair was hosted by the Department of Physics. As part of this fair, four stations were set up highlighting fundamental aspects of the funded NSF work in the field of magnetism. These stations included hands on demonstrations, make-and-takes, tours of research equipment, and experience completing manipulations in the glove box. Over 400 people attended the event, drawing all ages, genders and represented groups. The UMKC Chapter of SPS studied magnetism with a series of hands on experiments. Students built electric motors, speakers and studied diamagnetism of grapes. One PhD student supported by this effort is nearing his doctoral defense and disseminating results in internationally peer reviewed journals. One post-doc researcher and one GRA (thesis defense is planned for the fall of 2013) were partially supported by this effort in CNSE NDSU. Their recent results were published or submitted to internationally peer reviewed journals. GRA Chris Olson and UGRA Abby Matheson in CNSE NDSU lab UMKC Department of Physics students and Physics Fair attendees engaged in scientific and social activities in the lab and seminar room.

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