Inorganic Chemistry Seminar: Professor Jeff Rinehart, UC San Diego (Host: Hema Karunadasa)
Inorganic Chemistry Seminar: Professor Jeff Rinehart, UC San Diego (Host: Hema Karunadasa)
About the Seminar
"Designing molecular and nanoscale materials for bottom-up control of magnetism"
Magnetic applications are ubiquitous in modern technology, yet the available materials are relatively limited in number and tunability. The concept of modular, bottom-up design offers the possibility of atomic-level understanding and customization, yet is rarely effective because magnetic properties translate poorly between atomic, molecular, nano, and bulk scales. In this seminar, I will discuss our efforts to design magnetic systems with well-defined, robust magnetic parameters that maintain synthetically-intuitive behavior when translated across different size scales. The first topic discussed will be the use of well-defined magnetic nanoparticles to construct nanocomposite materials that mimic the functionality of tunnel junction magnetoresistors. I will describe our work demonstrating that magnetoresistance in these materials can be derived directly from the magnetic behavior of the individual nanoparticles, and the magnetoresistive response can be controlled through the addition of additional magnetic components within the composite. The second topic discussed in detail will be the extension of the unrivaled single-ion anisotropy of lanthanides to magnetically-coupled systems. By structuring the single-ion anisotropy for coordination tolerance instead of maximal strength, it becomes feasible to use knowledge of a molecular magnetic building unit as a guiding structural organization principle for building complex yet predictable magnetic structures.
About the Speaker
Jeffrey Rinehart grew up in Oconomowoc, WI and received his B.A. in Chemistry from Cornell University. During his time there he worked in the lab of Prof. Stephen Lee on characterizing structures of poorly-crystalline catalytic materials using a combination of powder x-ray diffraction and density functional theory. After graduating in 2005, he began graduate work with Prof. Jeffrey Long at University of California, Berkeley. There, he became fascinated with both the f-elements and especially their magnetic properties, eventually receiving his doctorate with a dissertation entitled "Magnetic Exchange Coupling and Single-Molecule Magnetism in Uranium Complexes." After graduating, he joined Prof. Daniel Gamelin's lab at the University of Washington as a postdoctoral scholar. His work focused on electronically and magnetically doped colloidal nanocrystalline semiconductors. He received a DOE Energy Efficiency and Renewable Energy (EERE) Fellowship during his second year to study how solar-induced Auger processes could affect voltage in doped semiconductor nanocrystal devices. Jeff was hired at UCSD as an assistant professor in the Department of Chemistry and Biochemistry in 2014. His laboratory spans synthetic, materials, and physical interests with a central focus on constructing magnetic materials with rationally-designed properties and new behavior that leverages the advantages of molecular and nano size regimes.