Knowledge center

Back to overview
Application note

Sample holders for air-sensitive materials

Air-sensitivity of a sample material (change of properties in direct contact with oxygen or/and water) is an important issue for many research fields. Besides other materials, a large number of pharmaceuticals and materials for gas storage applications requires an oxygen-/water-free atmosphere for their characterization.

On the one hand, sample material should be well protected from contact with air during a characterization process; on the other hand, a sample should still be accessible for the analytical tool in use. X-ray diffraction (XRD) has two main requirements (apart from good air-tightness) for such a protection: (i) a certain level of transparency for X-rays and (ii) minimal contribution to a diffraction pattern. Naturally, air-tightness and transparency to X-rays are two competing factors. Therefore an optimal sample holder should be chosen based on the specifics of a particular sample, mainly based on its degree of sensitivity to air/water (i.e. the speed of decomposition in direct contact with air/water).

To make this choice easier, PANalytical sample holders with foil protection for air-sensitive materials and Anton Paar domed sample holders are compared. Three main factors are benchmarked: air-tightness, X-ray transparency and a contribution to the XRD pattern. As testing material an extremely airsensitive compound was used: LiH (lithium hydride), which in direct contact
with air decomposes almost completely within one hour.

Download application note
You'll need Adobe Acrobat to read this file. Download it here

Share this article