APPLICATIONNOTE Brass Sample Preparation for Scanning Electron Microscopy Proper preparation of samples for ion milling increases milling process speed and improves the quality of the resulting scanning electron microscope (SEM) images. In this application note, a brass sample is mechanically polished and then milled using the Model 1060 SEM Mill in preparation for SEM imaging. Materials • • • • • • • • Hot plate CrystalbondTM adhesive Tripod-type holder Aluminum SEM stub Buehler grinder/polisher Abrasive disks (1200 grit) Diamond lapping films (3 and 1 µm) Fischione Model 1060 SEM Mill Mounting, Polishing, and Ion Milling Mount a brass sample (12.5 mm x 12.5 mm) on an aluminum SEM stub using a thermoset adhesive (e.g., Crystalbond). Apply pressure to the sample while the adhesive is hardening to ensure a more level surface for grinding and polishing (Figure 1). maintaining orientation so that scratches are consistent (Figure 2). Figure 2. Grind the sample on a 1200-grit abrasive disk, then polish the sample using 3 and 1 µm diamond lapping films. Use a tripod-type holder (e.g., an Allied TEM Wedge Polisher) to keep the sample steady and parallel to the abrasive surface, if desired (Figure 3). Use plenty of water to lubricate the surfaces and remove debris during the grinding and polishing process. Figure 1. Mount a 12.5 mm x 12.5 mm brass sample on an aluminum SEM stub using a thermoset adhesive. Figure 3. Brass sample and aluminum stub mounted on a handheld tool. Using the stub post as a handle, grind the sample on a rotating 1200-grit abrasive disk, Use 3 µm and then 1 µm diamond lapping films to reach a 1 µm finish; allow the sample to dry. E.A. Fischione Instruments, Inc. 1 Application Note Brass Sample Preparation for Scanning Electron Microscopy Load the sample and stub into the SEM Mill. Perform the milling operation with the following parameters: a single ion source set to 4 kV, 45% focus, and 4° beam angle for 30 minutes with continuous sample rotation. Imaging field emission scanning electron microscope. The overall quality near the center and edge of the sample is compared for magnifications of 1000X and 5000X (Figures 4-7). Some embedded grinding media remained as a result of the initial mechanical preparation. The ion-milled sample was imaged at 5 kV using the upper secondary electron detector in an Hitachi S-4700 Selected areas at the center were imaged at 20,000X with and without tilting to 45° (Figures 8-10). Figure 4. 5 kV SEM images acquired near the edge of the ion-milled brass sample (magnified 1000X). Figure 5. 5 kV SEM images acquired near the center of the ion-milled brass sample (magnified 1000X). Figure 6. 5 kV SEM images acquired near the edge of the ion-milled brass sample (magnified 5000X). Figure 7. 5 kV SEM images acquired near the center of the ion-milled brass sample (magnified 5000X). 2 E.A. Fischione Instruments, Inc. Application Note Brass Sample Preparation for Scanning Electron Microscopy Figure 8. 5 kV SEM images of selected areas of the ion-milled brass sample at 0° stage tilt (magnified 20,000X). Figure 9. 5 kV SEM images of selected areas of the ion-milled brass sample at 0° stage tilt (magnified 20,000X). E.A. Fischione Instruments, Inc. 3 Application Note Brass Sample Preparation for Scanning Electron Microscopy Figure 10. 5 kV SEM images of selected areas of the ion-milled brass sample at 45° stage tilt (magnified 20,000X). E.A. Fischione Instruments, Inc. 9003 Corporate Circle Export, PA 15632 USA Tel+1-724-325-5444 Fax+1-724-325-5443 [email protected] www.fischione.com ©2013 E.A. Fischione Instruments, Inc. All rights reserved. All trademarks are the property of their respective owners. Document Number AN005 Revision 00 07/2013 4 E.A. Fischione Instruments, Inc.