Real questions.
Practical answers.
Questions grouped by what you see. Start with the thing that looks wrong; you should not need to know which chapter contains the answer.
Where is the problem?
- How do I simulate the diffraction pattern of my own crystal?
- How do I calibrate the camera constant from a gold ring pattern?
- Is this segregation real or local magnification?
- How do I deal with overlapping peaks in my atom probe mass spectrum?
- When does Oliver-Pharr give the wrong hardness?
- Why does the top of my unloading curve bend backwards?
- My sample looks mirror polished but gives no EBSD pattern. Why?
- How do I prepare a sample for EBSD?
- Do I subtract the 70° EBSD tilt, or the 52° milling tilt, from my orientation data?
- Two grains have almost the same Euler color, so they are almost the same orientation, right?
Asked most often
Three steps, every time
Every answer on these pages follows the same three steps. They are the steps I use on my own data.
- 1Look at the raw data first.
The pattern before the map. The mass spectrum before the composition profile. The load curve before the hardness number. Most results that look wrong were fine until the software processed them.
- 2Blame the instrument before the sample.
Drift, tilt, detector gain, the wrong camera length, a bad reconstruction parameter. Check every one of these before deciding the material did something strange.
- 3Get a second technique to agree.
A feature that only one method can see is a hypothesis. When atom probe and 4D-STEM show the same thing in the same place, it is a result.
Check before you conclude
Before a number goes in a paper: these guides walk through what the instrument actually measured, which artefacts look like results, and what evidence would settle it.
Send it over.
An image, a pattern, a profile, and one line on what you expected to see. If it is not covered here yet, it may become the next question on these pages.