In situ TEM Raman spectroscopy and laser-based materials modification

• Published in: Ultramicroscopy 2017-07, Vol.178 (C), p.33-37
• Main Authors: Allen, F.I., Kim, E., Andresen, N.C., Grigoropoulos, C.P., Minor, A.M.
• Format: Article
• Language: English
• Subjects: In situ TEM; MoS2; Pulsed laser ablation; Raman spectroscopy
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/j.ultramic.2016.06.011

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 MoS2 combined with Raman spectroscopy, complimented by electron-beam diffraction and electron energy-loss spectroscopy. •Raman spectroscopy and laser-based materials processing in a TEM are demonstrated.•A lensed Raman probe is mounted in the sample chamber for close approach.•Localized laser processing is achieved using a tapered optical fiber.•Raman spectroscopy and pulsed laser ablation of MoS2 are performed in situ.