Novel MEMS-Based Gas Cell/Heating Specimen Holder Provides Advanced Imaging Capabilities for In Situ Reaction Studies

Allard, L. F., S.H. Overbury, W.C. Bigelow, M.B. Katz, D.P. Nackashi and J. Damiano, 2012
Atmosphere in situ TEM holder and manifold
Image courtesy of Microsc. and Microanal.

Abstract

In prior research, specimen holders that employ a novel MEMS-based heating technology (Aduro™) provided by Protochips Inc. (Raleigh, NC, USA) have been shown to permit sub-Ångström imaging at elevated temperatures up to 1,000°C during in situ heating experiments in modern aberration-corrected electron microscopes. The Aduro heating devices permit precise control of temperature and have the unique feature of providing both heating and cooling rates of 10⁶°C/s. In the present work, we describe the recent development of a new specimen holder that incorporates the Aduro heating device into a “closed-cell” configuration, designed to function within the narrow (2 mm) objective lens pole piece gap of an aberration-corrected JEOL 2200FS STEM/TEM, and capable of exposing specimens to gases at pressures up to 1 atm. We show the early results of tests of this specimen holder demonstrating imaging at elevated temperatures and at pressures up to a full atmosphere, while retaining the atomic resolution performance of the microscope in high-angle annular dark-field and bright-field imaging modes.

Impact Statement

The development of a new specimen holder that adapts the Aduro device into a “closed-cell” configuration. The adapted holder is designed to function within the 2 mm-thick pole piece gap of an aberration-corrected JEOL 2200FS STEM/TEM’s objective lens. It can also expose specimens to gases at pressures up to 1 atm. The researchers present the results of early tests using the holder at elevated temperatures and pressures up to one atmosphere. The resulting imaging retains the microscope’s atomic resolution performance in both high-angle annular dark-field and bright field modes.