title: Atomic-resolution STEM in the aberration-corrected JEOL JEM2200FS.
abstract: We report on the performance of our aberration-corrected JEOL-JEM2200FS electron microscope. This high-resolution field-mission TEM/STEM is equipped with a Schottky field-emission gun operated at 200 kV, a CEOS probe corrector, and an in-column energy filter. We focus on the performance of the probe corrector and show that the Si [110] dumbbell structure can be routinely resolved in STEM mode with the power spectrum indicating a probe size of approximately 1 A. Ronchigram analysis suggests that the constant phase area is extended from 15 mrad to 35 mrad after corrector tuning. We also report the performance of our newly installed JEOL-JEM2200MCO, an upgraded version of the JEM2200FS, equipped with two CEOS aberration correctors (and a monochromator), one for the probe-forming lens and the other for the postspecimen objective lens. Based on Young's fringe analysis of Au particles on amorphous Ge, initial results show that the information limit in TEM mode with the aberration correction (Cs = -3.8 microm) is approximately 0.12 nm. Materials research applications using these two instruments are described including atomic-column-resolved Z-contrast imaging and electron energy-loss spectroscopy of oxide hetero-interfaces and strain mapping of a SrTiO3 tilt-grain boundary. The requirements for a high-precision TEM laboratory to house an aberration-corrected microscope are also discussed.
authors.affiliation: Institute for Advanced Electron Microscopy, Brookhaven National Laboratory, Upton, NY 11973, USA. rfklie@uic.edu
authors.forename: Robert F
authors.initials: RF
authors.lastname: Klie
authors.forename: Craig
authors.initials: C
authors.lastname: Johnson
authors.forename: Yimei
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D005857:Germanium / Q000032:analysis; D006046:Gold / Q000032:analysis; D007089:Image Enhancement; D017348:Microscopy, Electron, Scanning Transmission / Q000295:instrumentation; D012680:Sensitivity and Specificity
chemical_list: D005857:Germanium; D006046:Gold