The D4 Endeavor fits in a unique niche in the XRD world. It’s basically the same thing as a Bruker D8, but built into a very compact cabinet with a large autosampler on top. These machines see heavy use in the cement, pharmaceuticals, and aluminum industries among others. Today we have one headed out to a new home. It started life in the pharmaceutical world, but had light use so it was a great candidate for refurbishment.
It’s easy to forget how much of our scientific work hinges upon comparative data. The entire field of metrology is concerned with the verification and maintenance of “standard reference materials” (SRMs). Creating a perfect reference standard essentially involves proving a negative. In the XRD world, we need to prove that there are no impurities, no crystalline defects, no unaccounted for thermal variations, no stress/strain effects present, and above all, that the first unit produced is effectively identical to the last
Plastic sample holders have been the default option XRD for decades. They’re inexpensive to make, good enough for most purposes, and very resistant to a wide range of chemicals. Seems like a “win” all around right? As long as they’re made correctly and from the proper materials, these work just fine. Spoiler alert: 3D printed thermoplastics have a distinct structure so if you try making your own, be sure they’re well out of the irradiated area. Comparison of the same powder
We’ve been experimenting with better ways to quantify the quality of XRD tubes in the shop. We use these tests on new and used tubes to monitor performance in two key areas. 1) Intensity 2) Spectral purity. What we’ve settled on is a test that involves a wavelength-dispersive approach which gives us a lot of intensity to work with while eliminating background scatter and fluorescence effects. Basically, we’re able to extract more information from the data because the “noise” is almost
Another fully-rebuilt, digital autosampler out in the wild. This one is on a system that already has one of our Si-Drift Detectors and an awesome ICDD Jade Pro/PDF-4+ software package. We’ve got all the fancy new hardware at our in-house lab, but when we need the absolute best data, this is our goto configuration.
Energy resolution 140eV under ideal conditions. All KB peaks eliminated electronically. W LA1 (8.40 KeV) lines eliminated from Cu KA1,2 (8.04 KeV) scans even with thoroughly contaminated tubes. Common fluorescence energies (i.e. Fe when Cu tube anodes are used) are greatly reduced. (Brehmstralung effects are impossible to remove completely) Most PSD detectors offer no better than 650eV. This allows for a great deal of fluorescence energy to pass as well as W LA1 from older Cu tubes. Low angle scatter The detector mounts in place of the
