In situ TEM Raman spectroscopy and laser-based materials modification

Abstract

We present a modular assembly that enables both in situ Raman spectroscopy and laser-based materials processing to be performed in a transmission electron microscope. The system comprises a lensed Raman probe mounted inside the microscope column in the specimen plane and a custom specimen holder with a vacuum feedthrough for a tapered optical fiber. The Raman probe incorporates both excitation and collection optics, and localized laser processing is performed using pulsed laser light delivered to the specimen via the tapered optical fiber. Precise positioning of the fiber is achieved using a nanomanipulation stage in combination with simultaneous electron-beam imaging of the tip-to-sample distance. Materials modification is monitored in real time by transmission electron microscopy. First results obtained using the assembly are presented for in situ pulsed laser ablation of MoS combined with Raman spectroscopy, complimented by electron-beam diffraction and electron energy-loss spectroscopy.

Understanding materials challenges for rechargeable ion batteries with in situ transmission electron microscopy

“…In addition to electrons, signals such as photons and secondary ions can also be generated in TEM. The capability of introducing light (laser) and simultaneously collecting the excited photons from targeted materials has been demonstrated previously for both Raman and cathodoluminescence spectroscopies 93 94 . Applying such techniques to battery systems, one can expect the real-time monitoring of battery temperature, chemical and compositional evolution and defect localization during the battery cycling inside TEM.…”

Exploring Photothermal Pathways via in Situ Laser Heating in the Transmission Electron Microscope: Recrystallization, Grain Growth, Phase Separation, and Dewetting in Ag0.5Ni0.5 Thin Films

“…Among the various characterization techniques (scanning) transmission electron microscopy [(S)TEM], and its associated spectroscopic complements, is one of the few techniques in which this information can be gathered with atomic scale resolution. Thus, there has been a concerted effort to develop various in situ accoutrements for the (S)TEM (Zheng et al, 2015; Taheri et al, 2016; Zheng & Zhu, 2017), examples include: in situ heating stages, gas (Jiang et al, 2018) and liquid cells (Chen et al, 2015), optical delivery and collection (Miller & Crozier, 2013; Allen et al, 2017; Joseph et al, 2017). Furthermore, over the past few decades, a few groups across the world have developed very complex and specialized ultrafast electron microscope or dynamic TEM systems using photo-cathodes that are exposed to short laser pulses to generate electron beamlets (and single electrons), that synchronously arrive at the sample in time relative to another pulsed laser directed at the same sample (Kim et al, 2008; Barwick et al, 2009; Liu et al, 2014; Barwick & Zewail, 2015; Li et al, 2016; Shorokhov & Zewail, 2016; Kaplan et al, 2017).…”

Optical and Optoelectronic Property Analysis of Nanomaterials inside Transmission Electron Microscope

“…Raman spectroscopy has also been performed inside TEM . Raman spectra could reveal useful information, such as chemical composition, defect density, structure chirality, temperature, stress/strain and magnetization of nanomaterials . Allen et al utilized a customized “InPhotonics” Raman probe installed inside a TEM to investigate laser‐induced microstructural changes in nanomaterials.…”

“…Allen et al utilized a customized “InPhotonics” Raman probe installed inside a TEM to investigate laser‐induced microstructural changes in nanomaterials. A tapered optical fiber threaded inside the sample holder was used for highly localized laser irradiation . This assembly was successfully employed to probe microstructural response in MoS 2 thin films during a laser‐ablation experiment.…”

“…c) Corresponding in situ Raman spectra of MoS 2 flake before and after laser irradiation. Reprinted with permission . Copyright 2016, Elsevier.…”