The ARES X-ray diffraction (XRD) laboratory has four powder XRD instruments that are used to identify unknown mineral phases and crystal structures in soil, rocks, and natural and synthetic minerals. Generated X-rays irradiate a material and are subsequently diffracted at characteristic angles related to atomic plane spacing of that material. A simple mathematical relationship called Bragg’s law relates atomic spacing with X-ray chart peaks that are used to identify minerals and provide crystal structure information.
Mineral identification is accomplished by a software driven comparison of over 400,000 patterns in the International Center for Diffraction Data (ICDD) database. Quantitative mineralogy can be accomplished with RIR, FULLPAT, and Rietveld techniques. Rietveld analysis can also provide crystal microstrain and crystallite size determinations along with other crystal structure information.
The Panalytical X'Pert Pro MPD with X'celerator detector (2.12° 2Θ collection window) provides high quality data acquisition of powdered samples. Three non-ambient stages allow XRD analysis from -190 to 900°C, 0 to 100 % relative humidity, and pressures of 0.01 to 10 bar. A non-ambient XRD capability is required to understand how temperature, pressure, and water content variations can affect mineralogy and crystal structures of materials.
The Rigaku MiniFlex benchtop XRD is capable of fast scans that drastically reduces data acquisition times without compromising data quality. The InXitu Terra is a field unit that allows XRD/XRF analysis in the field for rapid assessment of soil and rock mineralogy and chemistry. The InXitu CheminIV is optically configured similar to the Chemin XRD instrument that flew on the on Mars Science Laboratory Rover. The CheminIV instrument provides data of analog soil and rock that assists in the interpretation of the MSL-CheMin data.
Inside the X-ray Diffraction Laboratory: NASA Planetary Geologist Elizabeth Rampe carefully prepares powered samples to analyze on the CheMinIV X-ray Diffraction instrument. CheMinIV is an analog instrument to the Chemistry and Mineralogy (CheMin) instrument on-board the Mars Science Laboratory (MSL) rover, Curiosity.