Grazing Incidence Scattering

Grazing incidence X-ray scattering (GIXS) is used to study the structure of thin films and surfaces. In GIXS, a beam of X-rays is incident on the sample at a grazing angle, typically less than 1 degree. This means that the X-rays only interact with the top few nanometers of the sample. This makes GIXS a very surface-sensitive technique, and it can be used to study the size, shape, and orientation of nanoscale features on the surface of a sample.

GIXS techniques work at different scattering angles, including small-angle and wide angle scattering (named GISAXS and GIWAXS, respectively) as well as grazing incidence diffraction (GID). I16 is capable of a both small angle and diffraction scattering, making use of the suit of detectors available. In particular, the 6-axis diffractometer on I16 can be driven in such a way as to maintain the incident angle of the desired reflection; the so-called “fixed-alpha” mode.

GIXS is a powerful tool for studying a wide variety of materials, including thin films, polymers, ceramics, and semiconductors. It is used to study a variety of properties, including film thickness, crystallinity, surface roughness, and the presence of defects. GIXS is also used to study the interactions between materials, such as the adhesion of a thin film to a substrate.

Here are some of the applications of GIXS:

• Thin film characterization: GIXS can be used to measure the thickness, crystallinity, and surface roughness of thin films. This information can be used to control the properties of thin films, such as their optical, electrical, and magnetic properties.
• Surface defects: GIXS can be used to study the distribution and size of defects on the surface of a material. This information can be used to improve the quality of materials and to understand the mechanisms of material failure.
• Interfaces: GIXS can be used to study the structure and properties of interfaces between two materials. This information can be used to design materials with desired properties, such as high strength and toughness.

For more information about GIXS techniques, please see the excellent website by Detlef Smilgies:

https://www.classe.cornell.edu/~dms79/gisaxs/GISAXS.html

If you have any comments, suggestions or corrections, please contact a member of the beamline staff.