Materials Science Research Lecture

Webinar Link:

https://caltech.zoom.us/j/95708772987

Webinar ID: 957 0877 2987

Abstract:

Novel characterization techniques developed over the past two decades have revolutionized our ability to visualize the microscopic, atomic-scale processes that determine the functional properties of materials and devices. The overarching challenge is that the relevant time-scales and length-scales for these processes are typically short and small such that our view is often blurred out in time or in space. In this talk I will discuss two recent experiments along these lines: Part I will focus on the dynamics of hybrid perovskite materials, investigating the atomic and nanoscale processes that occur following absorption of photon. I will show how both femtosecond x-ray and electron scattering can be used to track the dynamics of polaron formation and associated transient elastic strain fields. I will also describe new experiments probing a class of hybrid perovskite nanocrystals where we show that light strongly modulates the local symmetry of these materials via tuning of octahedral distortions. In the second part of this talk I will describe experiments coupling in-situ transport and structural probes in the prototypical Mott insulator vanadium dioxide and new insight into the voltage-triggered insulator-to-metal transition. Synchronized time-resolved measurements of atomic motions and electronic transport in operating VO2 switches show that an isostructural phase forms transiently on microsecond time-scales. Our results represent the first direct observation of an electrically-driven transient metastable phase in a solid-state device.

More about the Speaker:

Aaron M. Lindenberg is an Associate Professor at Stanford University with joint appointments in the Department of Materials Science and Engineering and the Department of Photon Science. He received his B.A. from Columbia University in 1996 and his Ph.D. in Physics from the University of California, Berkeley in 2001. He was a Faculty Fellow at Berkeley from 2001-2003 and then b a staff scientist at the SLAC National Accelerator Laboratory from 2003-2007. He is a winner of the DARPA Young Faculty Award, the Department of Energy Outstanding Mentor Award, the Alfred Moritz Michaelis Prize, and was named a Terman Fellow and a Chambers Faculty Scholar at Stanford and an I.I. Rabi Scholar at Columbia.