22.08.2015   Nuclear and Radiochemistry

X-Ray Diffraction

In Section 10.2.2.4, the principle of the diffraction of waves was discussed in detail. It is not repeated here; only the main differences of the X-ray and neutron diffraction studies are summarized in Table 10.7.

Table 10.7 Differences Between the Characteristic Features of X-Ray and Neutron

Diffraction

X-Ray Diffraction

Neutron Diffraction

Interacting part of matter

Electron orbitals

Nuclei and magnetic field

Depth of introduction

104nm

Bulk

Cross section

Increases as the atomic number increases: the light elements can be analyzed only with difficulty or not at all

Independent of the atomic number: the light elements are seen well

Analytical possibilities

Structure of bulk and surface, mineral composition

Structure and morphology, magnetic interactions

The X-ray diffraction is applied to the structural analysis of crystalline sub­stances. Correct structural analysis can be obtained on monocrystals from small inorganic compounds to complex macromolecules. The study of polycrystals and crystalline powders is frequently used to study the qualitative and semiquantitative analysis of crystalline substances when diffractograms of the unknown samples can be compared to those of standards. A very important application is the study of the mineral composition of rocks. An example is shown in Figure 10.20.