Elastic airtight container for the compaction of air-sensitive materials.

We report on the design and fabrication of a simple and versatile elastic canister for the compaction and hot-pressing of air-sensitive materials. This device consists of a heated double-ended floating die assembly, enclosed in a compressible stainless steel bellows that allows the action of an external hydraulic press in a uniaxial motion. The enclosure is fitted with vacuum, gas, and electrical feedthroughs to allow for atmosphere control, heating, and in situ process monitoring. The overall chamber is compact enough to be portable and transferrable into and out of a standard laboratory glovebox, thus eliminating the problem of exposing samples to ambient atmosphere during loading and unloading. Our design has been tested up to 600 °C and 7500 kg-force applied load, conditions within which transparent ceramics of anhydrous halides can be produced.

High-throughput combinatorial database of electronic band structures for inorganic scintillator materials.

For the purpose of creating a database of electronic structures of all the known inorganic compounds, we have developed a computational framework based on high-throughput ab initio calculations (AFLOW) and an online repository (www.aflowlib.org). In this article, we report the first step of this task: the calculation of band structures for 7439 compounds intended for the research of scintillator materials for γ-ray radiation detection. Data-mining is performed to select the candidates from 193,456 compounds compiled in the Inorganic Crystal Structure Database. Light yield and scintillation nonproportionality are predicted based on semiempirical band gaps and effective masses. We present a list of materials, potentially bright and proportional, and focus on those exhibiting small effective masses and effective mass ratios.

Airtight container for the transfer of atmosphere-sensitive materials into vacuum-operated characterization instruments.

This paper describes the design and operation of a simple airtight container devised to facilitate the transfer of atmosphere-sensitive samples from a glovebox to the vacuum chamber of an analytical instrument such as a scanning electron microscope. The use of this device for characterizing the microstructure of highly hygroscopic strontium iodide ceramics by scanning electron microscopy is illustrated as an application example.

Laser-gain scanning microscopy: a new characterization technique for dopant engineered gain media.

We demonstrate an optical technique, called laser-gain scanning microscopy (LGSM), to map dopant concentration profiles in engineered laser gain-media. The performance and application range of this technique are exampled on a Nd(3+) concentration profile embedded in a YAG transparent ceramic sample. Concentration profiles measured by both LGSM and SIMS techniques are compared and agree to within 5% over three-orders of magnitude in Nd(3+) doping level, from 0.001 at.% to 0.9 at.%. One of the unique advantages of LGSM over common physical methods such as SIMS, XPS and EMPA, is the ability to correlate optical defects with the final doping profile.