Description
Bild 1: Arbeitsplatz Röntgenbeugungsanalyse
Picture 1: Workplace X-ray diffraction analysis

XRD = nondestructively method of analyzing structure of crystalsEquipment: D5000 matic (Siemens AG)Software phase analysis: EVA 2 (Bruker – AXS)Software Rietveldanalyse : Siroquant 3.0WZR ceramic solutions GmbH works with a D5000 matic diffractometer of Siemens company with a copper-tube (wavelength 1.54056 nm). Scintillation counter is used as a detector. Samples are measured due to reflection. Powder samples are usually, piece goods are even possible however.


General

X-ray diffraction
Bild 2: schematische Darstellung der RBA
Picture 2: schematic representation of the XRD

It is a nondestructively method of structure analysis of crystals. The most important issue is the identification of crystals within a sample. This is called x-ray phase analysis.A characteristic monochromatic x-ray is generated and steered to the analyzed sample. After interaction of crystals with the sample, the steered ray will be detected. The examination is based on the diffraction of the x-rays at the analyzed lattice planes. In principle, it is described by Braggs equation (fig. 3).

Bild 3: Wirkungsweise der RBA
Picture 3: Operation of the XRD

Powder diffraction (powder samples) leads to powder pattern (fig. 6). Visible are the registered intensities of the x-rays which are diffracted at the crystal lattice planes in response to the diffraction angle at a particular area of 2Theta. Peaks are compared with data base and identified thereby (qualified). In response to the intensity of the registered diffraction-data, it is possible to quantify the phases if qualification is completed.


Offer to clients

Bild 4: Detektoreinheit im Inneren der RBA
Picture 4: Detector unit in the interior of the XRD
  • Preparation- hard material to powder if needed
  • Qualifying of crystal phases (single and multiple phase mixture)
  • Quantifying phase amount within a multiple phase mixture
  • Quantification of amorphous phase amount using an internal standard

Below 5wt% it is not possible to determine phases reliable. The error of quantitative determination is reduced by an higher amount of phases however.In general:

  • Qualitative analysis: dmax: < 50µm, 1g
  • Quantitative analysis: dmax: <63µm, 2g

Example of Methods

Bild 5: Probengreifer über einer Pulverprobe
Picture 5: sample looper over a powder sample
  • Natural as well as raw material and products of technical applications
  • Raw materials (ceramic and its products; products of medicine application; refractories)
  • Cement materials
  • Metal, corrosive products

XRD is able to determine

  • Stoichiometric composition of phases
  • Crystalline impurities
  • Phase transition (quartz into cristobalite)
  • Mineral reactions

Applications