In the second installment of the powder X-ray diffraction (PXRD) basic course, how to select instrument configurations to obtain high-quality data was described. This third installment provides information on how to prepare samples and determine the best measurement conditions to obtain high-quality data. Regarding sample preparations, the type of sample holders, the effect of grain size of the sample, and the impact of the eccentricity and asperity of the sample surface must be taken into consideration.
In most PXRD measurements, a glass sample holder is usually filled with sample. However, other appropriate sample holders should sometimes be selected based on the chemical properties, composition, and shape of the sample, which will allow you to obtain high-quality data with high resolution and low background. Also, the impact of preferred orientation can sometimes be suppressed. Appropriate optics should also be used for the selected sample holder. The following chapters and sections will describe the details of sample preparation and measurement conditions, along with a few tricks and traps.