Scanning Electron Microscope

Tescan VEGA3: GMU Variable Pressure Scanning Electron Microscope

In 2021 Matty Mookerjee et al. was awarded an NSF grant to purchase a Tescan VEGA3: GMU Variable Pressure Scanning Electron Microscope. Operating protocol will be posted here when fully developed.

Tescan VEGA3: GMU Variable Pressure SEM with a large sample chamber, multiple ports (12+) that are ideally oriented for combined EBSD/EDS analysis and large-area mapping, motorized compucentric 5-axis stage, Low Vacuum Secondary Electron (SE) detector, and a motorized and retractable BackScattered Electron (BSE) detector. This system includes a variety of safety features such as touch alarms, sample holder profiles which inform the software of the dimensions of the holder to limit the range of movement and avoid collisions (these limits can be overridden by expert users, but not students), “Safe Movement Mode,” and 4 levels of user expertise that define the “rights” of given users. The software allows for live 3D stereoscopic imaging (particularly impressive for large lecture class demos), and remote access and control of the SEM. Tescan microscopes utilize unique, 4-lens optics which provides 5 distinct operating modes (Resolution, Depth, Field, Wide Field, and Channeling). In particular, the Wide Field mode simplifies navigation and will be useful for classroom demonstrations (see images below). Additionally, the X-Positioner optical stage navigation software allows the operator to use a variety of types of imagery (e.g., optical photomicrograph, x-ray imagery, iPhone photograph, etc.) to navigate around the sample. The ImageSnapper software automatically creates stitched together/panoramic images of large sample areas.

Tescan Panchromatic Cathodoluminescent (CL) Detector (fully integrated with the Tescan microscope control software) and the Oxford Instruments Symmetry Electron BackScatter Diffraction (EBSD) Detector, and Energy-Dispersive X-ray Spectrometry (EDS) UltimMax 65 Silicon Drift Detector. Additionally, this microscope will be equipped with Tescan’s Electron Beam Lithographic Package in order to be able write patterns into magnetic thin films. Further, we will be purchasing a Cressington 208C High Vacuum Turbo Carbon Coater for SEM sample preparation in order to diversify the types of projects that this instrument can collect data for.