X-ray diffraction (XRD) is an analytical technique looking at X-ray scattering from crystalline materials. Each material produces a unique X-ray "fingerprint" of X-ray intensity versus scattering angle that is characteristic of it's crystalline atomic structure. Qualitative analysis is possible by comparing the XRD pattern of an unknown material to a library of known patterns.

XRD is complementary to spectroscopic techniques like X-ray fluorescence (XRF). For example, XRF can tell you that a material is composed of iron and sulfur, but XRD can tell you that both FeS2 and elemental Fe are present. Further, since XRD works with any crystalline solid, there is almost no limit to the types of materials that can be studied.

What X-ray diffraction systems ?

About 95% of all solid materials can be described as crystalline. When X-rays interact with a crystalline substance (phase), one gets a diffraction pattern. The X-ray diffraction pattern of a pure substance is, therefore, like a fingerprint of the substance. The powder diffraction method is thus ideally suited for characterization and identification of polycrystalline phases.

Today about 50,000 inorganic and 25,000 organic single component, crystalline phases, diffraction patterns have been collected and stored on magnetic or optical media as standards. The main use of powder diffraction is to identify components in a sample by a search/match procedure. Furthermore, the areas under the peak are related to the amount of each phase present in the sample.

Thermo Fisher Scientific produces an X-ray system with a wide range of components, meeting the customer's needs in almost any field of X-ray analysis. There is one basic size of X-ray cabinet, one basic type of X-ray goniometer (vertical), Peltier cooled solid-state detector, and multiple attachments/auxiliary components that combine to make Thermo Scientific diffraction systems flexible for a wide range of applications.