Local Atomic Structure Analysis Using the Atomic Pair Distribution Method

Powder diffraction is a major component of any condensed matter scientist’s arsenal, providing the investigator a way to directly map the location of atoms inside of a material. The most common diffraction experiments provide insights into the average atomic structure of materials, which can break down when materials have lowered local symmetry, or are disordered. Analysis of the pair distribution function (PDF) was already an important tool in the study of liquids and glassy structures when it was shown that it can be applied to crystalline materials to gain insight into local disorder and dynamics. This paper will discuss powder diffraction analysis of crystalline materials, comparing standard powder diffraction analysis and PDF methods, and discuss the relevant differences in these techniques. The paper concludes with a discussion of experimental concerns for conducting PDF measurements.