Grazing incidence X-ray diffraction

X-rays have been used for decades to study the structure of bulk crystalline materials. They interact weakly with matter compared to (say) electrons, and thus are not normally thought of as surface-sensitive. However, in recent years techniques have been devised that, in combination with the availability of intense collimated beams from synchrotron sources, have transformed X-rays into a versatile and powerful tool for the study of surfaces, monolayers and ultrathin films. This article briefly describes the principles of grazing incidence X-ray diffraction, and gives a few examples of results obtained using this technique.