Dr. Tim Strobel [Grophysical Lab, CIW, USA]

Title:     Novel compounds and allotropes based on group-14 elements

Time:   10:00 – 11:00 AM, June 9, 2015, Tuesday

Place:   Conference room 201, Build 6, HPSTAR (Shanghai)

Host:     Dr. Mao

Abstract:

Novel materials are required in order to make both fundamental and applied advances over a vast range of areas. While traditional materials synthesis relies on thermochemical methodologies, i.e., using temperature to overcome activation energy barriers and stimulate chemical bond rearrangement at ambient pressure, high-pressure synthesis methods show promise to create novel materials with superlative properties and give access to an entirely new materials space. In this talk I will provide an overview of our recent work on new, recoverable compounds and allotropes based on group-14 elements, and discuss a novel synthesis strategy that utilizes recoverable high-pressure materials as starting points for subsequent atmospheric-pressure manipulation. Specifically, I will provide an overview of high-pressure, light-metal silicides, germanides and carbides, and discuss how these recoverable materials can serve as valuable chemical precursors for the formation of phases including a new allotrope of silicon with a quasidirect band gap of 1.3 eV and a new, mixed sp2-sp3 family of carbon allotropes that consist of interpenetrating graphene sheets.

Biography of the Speaker:

Dr. Tim Strobel's research is centered on the synthesis and characterization of novel materials for energy and advanced applications. New materials are synthesized using unique pressure-temperature conditions and through innovative processing pathways. Of particular interest are extended structures rich in carbon, silicon and germanium, as well as hydrogen-rich molecular systems. He received his B.S. (2004) and Ph.D. (2008) in Chemical Engineering from the Colorado School of Mines. In 2008 he joined the Geophysical Laboratory of the Carnegie Institution of Washington as a Carnegie Postdoctoral Fellow and was appointed Staff Scientist in 2011.