Intro to XRD

After my Quantifying Li post went out I received a particularly funny email…

Backstory: Dr. Gallaway was my principle investigator (PI or boss for those of you who haven’t had the extreme pleasure of grad school) and with some light nudging he had me develop a way to relate x-ray diffraction (XRD) data to lithium content based on a previously published relationship. 

The bulk of my thesis was based on this, and this is the first (and hopefully last) time that I will refer you to one of my own papers.

This series will cover the materials science basics needed to analyze battery materials, angle dispersive XRD (ADXRD), energy dispersive XRD (EDXRD), linear regression and refinement, and using XRD data to quantify Li content. 

Basically this paper took ~3 years of my life so we will go through the background skills and expertise that I had to build that didn’t even make it into this paper and which I am not at all bitter about. Not bitter at all.

Let’s get into it.

At a high level, XRD measures how X-rays interact with periodically arranged atoms in a crystal.

Because the atoms are arranged in a repeating pattern, X-rays scatter in a predictable way, producing diffraction peaks.

Read those peaks correctly, and you get structural information. Read them sloppily, and you’ll be confidently wrong.