Evaluation of High-Resolution STEM Imaging Advancement Under Gas-Environment with Open Window MEMS Holder and Gas Injection System

Abstract

Observation of reaction processes in the in-situ environment has been increasingly demanded to understand the properties of catalysts and fuel cells with a transmission electron microscope (TEM). Insitu TEM / STEM play an important role to analyze the structural changes at the atomic scale under the heating and gas environments. Furthermore, with the size shrinkage of the target materials or devices, in-situ real time imaging with a sub-Angstrom resolution has become more demanded. The analytical 200 kV cold field emission (CFE) TEM HF5000 (Hitachi High-Technologies) equipped with an inhouse designed probe-forming aberration corrector was introduced and the imaging performance of the environmental real time scanning transmission electron microscopy (STEM) was reported [1][2]. The HF5000 key feature of in-situ STEM is a live scanning acquisition (25 frames/sec) that allows real-time observation and video recording of dynamic atomic scale reactions. HF5000 provides clear real time imaging for such as structure change and elemental diffusion processes during reaction. Besides DF / BF live images, a secondary electron image in the atomic scale can be simultaneously acquired with the rich high resolution surface morphology information in-situ.

Reversing sintering effect of Ni particles on γ-Mo2N via strong metal support interaction

“…Moreover, it is hard to derive the surface information from the recorded 2D projection when samples were thick (above 100 nm) or in irregular shape. The new electron microscopy technique of environmental probe-corrected scanning transmission electron microscope equipped with secondary electron detector was applied to achieve the simultaneous acquisition of SE image and STEM image (STEM-ADF, STEM-BF) with an atomic spatial resolution (below 1 Å) 37 . Utilizing the surface sensitive low energy secondary electron caused by interaction between the primary beam and object, SE images showed a powerful ability to analyze surface morphology on bulk materials, regardless of the thickness and Z contrast of the metal on the support 38 .…”

Reversing sintering effect of Ni particles on γ-Mo2N via strong metal support interaction

“…Moreover, it is hard to derive the surface information from the recorded 2D projection when samples were thick (above 100 nm) or in irregular shape. The new electron microscopy technique of environmental probe-corrected scanning transmission electron microscope equipped with secondary electron detector was applied to achieve the simultaneous acquisition of SE image and STEM image (STEM-ADF, STEM-BF) with an atomic spatial resolution (below 1Å) 35 . Utilizing the surface sensitive low energy secondary electron caused by interaction between the primary beam and object, SE images showed a powerful ability to analyze surface morphology on bulk materials, regardless of the thickness and Z contrast of the metal on the support 36 .…”