Presenter: Prof. Xiaoji Xu (Lehigh University)
Topic: Peak ForceInfrared Microscopy: Nanoscale Infrared Microscopy with sub 10 nm SpatialResolution
Time: 9:30 a.m., Dec.18th (Monday)
Location: ConferenceRoom B, BLDG 909-1F
Abstract
While Abbe’s optical diffraction limit prevents nanometer-scale spatialresolution for conventional microscopy and spectroscopy, the combination ofoptics and scanning probe microscopy provides a way to bypass the diffraction limit.One type of imaging technique is to utilize the near-field light scatteringfrom a metallic AFM tip to locally probe the optical properties of the sample.The other type of high spatial resolution imaging technique is to measure thelight-induced thermal expansions in the sample and related that to the localoptical or infrared absorption. In the first part of the presentation, I will first present our latest invention ofpeak force infrared (PFIR) microscopy that provides infrared imaging, broadbandspectroscopy, and mechanical property mapping at a spatial resolution as highas 6 nm. I will describe applications ofPFIR microscopy on the characterization of block copolymers, urban aerosols(particulate matter PM2.5), organic photovoltaics and bacterial cell walls. Then,I will describe our recent development of the scattering-type infrarednear-field microscopy for three-dimensional mapping of near-field responses ofpolaritonic materials and a route to incorporate scattering-type infrarednear-field microscopy with ultrafast lasers. The exploration of nanoscalephenomena will be facilitated by thesenanoscale infrared imaging techniques in revealing hidden secrets of thenanoworld.
Biography
Xiaoji Xu established his researchgroup at Lehigh University as an assistant professor since 2014. Before at LehighUniversity, he was a postdoctoral fellow at the University of Toronto, andUniversity Colorado Boulder. He receivedhis B.S. in Chemistry from PekingUniversity in 2004 and Ph.D. in ChemicalPhysics from The University of British Columbia, Vancouver, Canada in 2009. Hisresearch focus is on chemical sensitive nanoscale imaging, ultrafast laserspectroscopy, and development of the analytical instrumentation. He holds three patents (licensed to industrialpartners). Since he joined Lehigh, hehas published seven papers including Nat. Commun., Sci. Adv. and ChemCommun and received the Class’ 68research fellowship from Lehigh University.
Contact:Prof. Le He
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