E-beam chemistry and SEM imaging were performed using a Zeiss Gemini system. Using a 15 µm condenser aperture which begets a 1.6 nm probe size. To obtain control of the pressure range in the Zeiss Gemini system, we used the variable pressure (Nano-VP) mode which placed a pressure-limiting aperture (called a beam-sleeve) in the path between the e-beam column and the vacuum chamber; the 350 µm aperture was used in order to reduce skirting effects.