Focused Ion Beam
The MCP Thermo Scientific Helios G4 UC Focused Ion Dual Beam instrument equipped with a monochromated electron beam for scanning electron imaging and the Tomahawk ion column. The G4 will be upgraded to a Helios 5 with Multichem Gas Injection System which has 5 mixable sources. The electron column has a resolution of better than 0.6 nm and the ion column has a resolution of 1 nm. The ion beam is produced from a liquid Ga source that ionizes the Ga and focuses the beam down to a nanometer in diameter. This beam is mainly used for two purposes: 1) milling and shaping a sample, 2) depositing either carbon or Pt, or W. We use the FIB for several purposes: 1) to produce thin membranes for the TEM, 2) to examine the textural and compositional state of the samples at and just below the surface, 3) to fabricate nanometer-sized structures and devices, 4) to examine the chemical distribution of elements quantitatively, 5) examine the crystallographic orientation of materials using both electron backscattered diffraction (EBSD) and Transmission Kikuchi diffraction (TKD) methods, and image with a cathodoluminescence detector. By digging trenches into the surface of the sample, we can get a cross sectional view of the changes with depth and build a 3 dimensional reconstruction of textures, crystallographic orientations, and compositional variations.