90 likes | 224 Views
Advanced FE-SEM : from Nano-imaging to Chemical and Structural Analyses. Chi Ma Division Analytical Facility Division of Geological and Planetary Sciences, Caltech chi@gps.caltech.edu http://www.gps.caltech.edu/facilities/analytical/. CSEM 2003.
E N D
Advanced FE-SEM: from Nano-imaging to Chemical and Structural Analyses Chi Ma Division Analytical Facility Division of Geological and Planetary Sciences, Caltech chi@gps.caltech.edu http://www.gps.caltech.edu/facilities/analytical/ CSEM 2003
A high-resolution analytical scanning electron microscope (LEO 1550VP) was installed in Sept 2002 at Caltech GPS Division Analytical Facility and became available for campus-wide use in Dec 2002. The new PC-based LEO 1550 SEM is a multipurpose state-of-the-art instrument capable of SE, BSE, variable pressure SE, CL imaging, high-resolution imaging (down to 1 nm), chemical and crystallographic analyses.This is a field emission SEM which can operate at voltages ranging from 200 V to 30 kV and at magnifications ranging from 20 x to 900 kx for a wide variety of applications. The 1550 is equipped with two state-of-the-art accessories. The first, an Oxford energy-dispersive X-ray spectrometer (EDS), can determine and map the elemental distribution within a region or along a line, or perform a quantitative chemical analysis of a point or region. The other accessory, a HKL electron backscatter diffraction system (EBSD), can determine the crystal structure and orientation of the sample at a specific point, and conduct orientation mapping and phase identification at submicron scale. The SEM was acquired and is supported in part by the MRSEC program of the NSF under DMR-0080065. CSEM 2003
The analytical SEM is having a wonderful impact on campus. Since Dec 2002, about 85 users from 40 faculty research groups on campus and JPL have used the SEM. They are from: Material Sciences EE, ME, CS Applied Physics Aero-engineering Bio-engineering Biology Chemistry Chemical Engineering Physics Geology Geochemistry Geophysics Geobiology CSEM 2004
Imaging Capabilities(5 electron detectors) • High resolution Imaging – In-Lens SE1 • Low Voltage Imaging (200V – 5kV) – better surface imaging due to reduced beam penetration • Compositional Contrast Imaging - BSE • Orientation Contrast Imaging – FSE • Variable Pressure SE Imaging (3Pa-100Pa) • Cathodoluminescence Imaging • STEM imaging CSEM 2003
Chemical Analysis - EDS • Detector capable of detecting Be to U • Quantitative EDS analysis -Quantitative results with a relative accuracy of better than 5% and detection limits of better than 0.5% can be readily obtained. • X-ray mapping Structural Analysis - EBSD • Orientation mapping – texture analysis • Phase ID CSEM 2003