X-ray diffraction and X-ray fluorescence (XRF) laboratory

The X-ray diffraction (XRD) laboratory is equipped with a Philips PW 1730 X-ray diffractometer controlled by PC-APD software. Graphite monochromator and Cu tube are used. Facilities for a range of sample preparation methods are available. Application areas cover qualitative and semi-quantitative mineralogical characterization of geological samples (especially low grade metamorphites, soils, clays, coals, kerogens, Mn-ores, etc.), calibrated illite, chlorite and kaolinite "crystallinity" measurements, crystallite size and lattice strain calculations are the main tasks of the laboratory. Beside geological samples, the laboratory is also an expert in investigation of samples of cultural heritage (glass, pigment, ceramic, building materials).

The XRF laboratory is equipeed with a Philips PW 1410 type wavelength-dispersive X-ray fluorescence spectrometer controlled by Philips X31 version 2.13 software is used at the Institute for Geochemical Research. X-rays are generated at 50 mA and 50 kV by X-ray tube with chromium anode. The following analysing crystals are used to separate the various wavelengths of characteristic X-ray radiation: LiF (200) for elements heavier than Ca, PE between Al and K, ADP for Mg, and TlAP for Na. For the detection of higher wavelengths of fluorescent radiation produced by light elements gas-filled proportional detectors are employed, while short wavelengths (heavy elements) are measured with a scintillation detector. This instrument is capable of measuring all elements from fluorine to uranium - at trace levels often near part per million depending on the atomic number, and up to 100%. 
Geological samples (rocks, soils, minerals) are powdered and pressed (around 5 tons per square centimetre) directly into aluminium-rings with additional use of a binder material (20% boric acid).

 


 

Institute for Geochemical Research