Recovered Diamond Anvil Cell (DAC) Sample Analysis
After running a DAC experiment, we transfer the sample to the FIB where we section the entire disc to locate the laser heated area. We then perform backscattered electron (BSE) imaging and energy dispersive x-ray spectroscopy (EDS) to understand the processes that occur under high pressure and temperature.
Key Collaborators: Michael Walter, Zack Geballe, Alex Goncharov, Yingwei Fei
Sample mounted for FIB
The sample is cut free from the gasket and mounted on the edge of a silicon (Si) wafer. There is a ring of rhenium (Re) surrounding the sample.
Revealing the hot spot
Using very high current milling (2.5 μA) we mill right up to the heated spot. Then we use lower currents to section into the middle of the heated spot.
Electron imaging
Once we have located the center of the heated spot, we perform secondary electron (SE) and backscattered electron (BSE) imaging of the material.
EDS
Finally, we use a high energy electron beam to generate characteristic x-rays that are detected with our EDS system. The EDS software will assign a color to a specific element. Here, the green corresponds to aluminum (Al),
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the blue corresponds to calcium,
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and the yellow corresponds to iron (Fe). Thus, we can identify how these elements segregated during the DAC experiment.