Dynamic environmental transmission electron microscopy

Dynamic environmental transmission electron microscopy (DETEM);Transmission electron microscopy (TEM);Dynamic transmission electron microscopy (DTEM);Zuo;van der Veen;Electron microscopy

Lai, Jocelyn Chu ; van der Veen, Renske ; Zuo ; Jian Min

关键词: Dynamic environmental transmission electron microscopy (DETEM);    Transmission electron microscopy (TEM);    Dynamic transmission electron microscopy (DTEM);    Zuo;    van der Veen;    Electron microscopy;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/97788/LAI-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The development of a dynamic environmental transmission electron microscope (DETEM) at the University of Illinois Urbana Champaign is documented in this thesis. The proposed apparatus is the first of its kind, combining the power of high-resolution electron imaging and diffraction of TEM, the time resolution provided by pulsed laser, and the in-situ capabilities of environmental transmission electron microscopy (ETEM) while also providing fast imaging capability using a CMOS pixel sensor for direct electron detection and a photoelectron gun. When operated in continuous imaging mode, the time resolution of the DETEM will be at least a factor of 30 larger than conventional electron microscopes. With the pulsed laser, dynamic events of reversible and irreversible processes in materials can be imaged and recorded with either stroboscopic or single-shot movie-mode methods. To develop the DETEM the Hitachi H-9500 300 kV TEM installed at the Frederick Seitz Materials Research Laboratory, has been modified to accommodate the optics to allow various pump-probe methods to take place for in-situ experiments. The design and assembly of the pump and probe optical inserts are described, along with the optical layout and its alignment that delivers the pump and probe laser beams. Characterization of the nanosecond pulsed laser system being implemented for the DETEM and ex-situ measurements of power threshold were also performed and recorded.