LDRD seminar: Nov. 20
Three Argonne researchers will discuss their Laboratory-Directed Research and Development (LDRD) sponsored work at the LDRD Seminar Series presentation Tuesday, Nov. 20, 2018, at 12:30 p.m. in Building 212, Room A157. All are welcome to attend.
Visit the LDRD website to view upcoming seminars.
“The Search for Next Generation Nuclear Radiation Detectors: A Materials Design and Discovery Approach” by Senior Scientist Mercouri Kanatzidis (MSD)
Gamma-ray (g-ray) detection and spectroscopy is the quantitative determination of the energy spectra of g-ray sources, and is of critical value in diverse and critically important technological and scientific fields such as the nuclear industry, nuclear medicine, medical imaging, national security for the nonproliferation of nuclear materials, geochemical investigations and astrophysics. However, detectors that can resolve the specific energies of g-rays from specific nuclear sources at room temperature are rather difficult to develop because of a wide array of strict requirements including high stopping g-ray power, extremely low trapping of electrons and holes, long carrier drift lengths and cm-sized single crystal size. To date the available semiconductors for this job are inadequate for various reasons including cost, stability, etc. I will describe a solid state chemistry and materials science approach that has been successful in identifying many new promising materials for hard radiation detection.
Mercouri Kanatzidis was born in Thessaloniki, Greece. He is professor of chemistry and materials science and engineering at Northwestern University and senior scientist at Argonne. His research areas include: Inorganic chemistry, solid state and coordination chemistry of chalcogenide compounds. Design of new materials, exploratory synthesis, thermoelectric materials, nanostructured materials, intermetallics, superconductors and nuclear radiation detectors.
He is the recipient of many honors and awards, including: Presidential Young Investigator Award. National Science Foundation, 1989-1994; ACS Inorganic Chemistry Division Award: EXXON Faculty Fellowship in Solid State Chemistry, 1990; Beckman Young Investigator, 1992-1994; Alfred P. Sloan Fellow 1991-1993; Camille and Henry Dreyfus Teacher Scholar 1993-1998; Michigan State University Distinguished Faculty Award 1998; Sigma Xi 2000 Senior Meritorious Faculty Award; University Distinguished Professor MSU 2001; John Simon Guggenheim Foundation Fellow 2002; Alexander von Humboldt Prize, MRS Fellow 2010; Royal Chemical Society DeGennes Prize 2015; Elected Fellow of the Royal Chemical Society 2015; the ENI Award for the “Renewable Energy prize” category; the ACS Award in Inorganic Chemistry 2016; and the American Physical Society 2016 James C. McGroddy Prize for New Materials.X
“In situ X-ray Studies of the SrCoOx Phase Transition” by Materials Scientist Dillon Fong (MSD)
The aim of this project is to exploit third-generation synchrotron sources like the Advanced Photon Source (APS) to conduct fundamental studies on the dynamics of phase transitions in complex oxide materials — materials known to exhibit a wide variety of phases ranging from superconducting to ferroelectric and antiferromagnetic to multiferroic. In this two-year project, we focus on understanding the dynamics of electrochemically driven phase transitions in the cobaltites, a correlated electron systems with properties that vary from insulating to metallic or antiferromagnetic to ferromagnetic, depending on the Co oxidation state. We employ X-ray photon correlation spectroscopy to understand the dynamics of the phase transition.
Dillon Fong is a scientist in the Materials Science division. He has helped to develop several in situ synchrotron tools at the APS, including a combined scattering hard X-ray photoelectron spectrometer and a system for operando studies of catalytic behavior. He is a recipient of the 2009 Presidential Early Career Award for Scientists and Engineers and the 2013 Argonne National Laboratory Distinguished Performance Award.
“Controlling Oxygen Vacancies to Realize Novel Electronic and Magnetic States in Complex Oxides” by Physicist Anand Bhattacharya (MSD)
The complex oxides are known to host a broad range of electronic and magnetic states, which can be tuned by a variety of ways including strain and doping. Their properties are also known to be highly sensitive to the presence of oxygen vacancies, which in some materials can be controlled in a reversible manner. This raises the possibility of using oxygen vacancies to switch electronic and magnetic properties. I will present our work in controlling oxygen vacancy formation in SrFeO3 which is known to be a helical antiferromagnet, and where the resistivity can be changed by several orders of magnitude depending on the level of oxygen vacancies in the system.
Anand Bhattacharya is a physicist in the Materials Science division. He likes to make and study thin films and heterostructures of materials with interesting electronic and magnetic properties.