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c. 2.35 Å. (220). Remarkable Size-Dependent Magnetic Properties of Europium Chalcogenide Nanocrystals James Dickerson, Vanderbilt University, DMR 0757380. Our work explores how the size and local crystallinity of a nanocrystal directly influences the object’s magnetic and optical properties.

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  1. c 2.35 Å (220) Remarkable Size-Dependent Magnetic Properties of Europium Chalcogenide NanocrystalsJames Dickerson, Vanderbilt University, DMR 0757380 • Our work explores how the size and local crystallinity of a nanocrystal directly influences the object’s magnetic and optical properties. • Highlights • We synthesized the world’s first nanoscale crystals of europium telluride (EuTe). • Bulk EuTe is an antiferromagnetic material, meaning that the material expresses minimal-to-zero net magnetic moment in an elevated magnetic field due antiparallel magnetic ordering of moments. • When reduced to nanoscale, magnetic ordering at the surface differs from that within the center of the object. • This difference reveals a rarephenomenon of superantiferromagnetic ordering. • Our results reveal that rare and potentially exploitable magnetic properties can be realized through control of the object’s size and composition. • 1. W. He, S. Somarajan, D.S. Koktysh, and J.H. Dickerson, Nanoscale 3, 184, 2011 b a 2.3 Å (200) d a) & b) TEM images of 6.5 nm crystalline EuTe nanocrystals. c) TEM image of EuTe nanospindle. d) Magnetic characterization of EuTe nanocrystals as a function of temperature. Changes in slope of the inset graph (inverse susceptibility vs. temperature) reveal a rare phenomenon called superantiferromagnetism.1

  2. Remarkable Size-Dependent Magnetic Properties of Europium Chalcogenide Nanocrystals James Dickerson, Vanderbilt University, DMR 0757380 Undergraduate students as well as graduate students have worked on the synthesis and characterization of europium chalcogenide nanomaterials over the past year. Partnered with the Vanderbilt University Physics and Astronomy Department’s REU program, funding from this grant supported the summer research experiences of an excellent rising sophomore (top image) who will be the lead author on a manuscript on chalcogenide nanoparticle synthesis and a co-author on the magnetic properties of ternary europium chalcogenide (Eu2O2-xSx) nanocrystals. Support from this grant has allowed the lead graduate student (bottom image) to conduct invaluable high-field magnetic experiments at the National High Magnetic Field Laboratory in Tallahassee, FL as well as give an invited symposium talk at the 2010 Fall ACS Meeting in Boston, MA.

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