Synthesis of Intermetallics in Molten Metal Mixtures Susan E. Latturner, Florida State University, DMR 0547791

1. Synthesis of Intermetallics in Molten Metal MixturesSusan E. Latturner, Florida State University, DMR 0547791 Our research into the use of early lanthanide/late transition metal eutectic mixtures as reaction media has yielded crystals of several new phases with interesting magnetic properties. La/Ni flux (mp 532 °C) is a combination of an active metal (La is incorporated into all products) and an inert component (Ni). The reaction of Fe, Sn, and Al in La/Ni flux produces a family of related structures, all featuring layers of linked Fe icosahedra capped with aluminum atoms. If the aluminum is replaced by carbon, a completely different structure type is formed, featuring isolated tetrahedral clusters of iron atoms capped on each edge with carbon; these clusters exhibit spin frustration. Replacing La with Ce, Pr, and Nd will yield even more complex magnetic behavior. Learning about how these different iron layers or clusters are stabilized (what elements promote their formation, at what temperatures they form) may allow eventual control over product structures. La21Fe8Sn7C12 Fe/Sn/X in La/Ni Flux Melt X = C ? X = Al ? Ideal Fe tetrahedra with antiferromagnetic coupling leads to spin frustration Left: cubic La(Fe1-xAlx)13. Center: tetragonal La6[Fe1-xAlx]13Sn. Right: new tetragonal La22[Fe1-xAlx]26Sn7-d Antiferromagnetic coupling between iron layers in the tetragonal structures shifts to lower temperatures as layers are further separated (from TN=115K to TN=20K)

2. Synthesis of Intermetallics in Molten Metal MixturesSusan E. Latturner, Florida State University, DMR 0547791 This research has facilitated collaboration with several groups in NHMFL (Tozer and Wiebe groups). Assistance from Dr. Brent Greska in the Engineering Department was vital to building a Sieverts apparatus for hydrogen absorption studies on our compounds. This device (left) can be used for a variety of gas sorption studies and will be used by several research groups in the FSU Chemistry department. In addition to publishing our work in chemistry journals, we have also put together a presentation for the GEOSET website (left), which promotes education and open access to presentations on current scientific topics of interest. The GEOSET website allows viewers to watch a video-taped presentation (left) accompanied by the slide show that is being presented (right). From the Latturner group, Jeff Whalen presented his talk on synthesis of lightweight intermetallics in Mg-rich fluxes and measurement of their hydrogen absorption properties. http://geoset.fsu.edu/gradprojects.html