Crystal quality evaluation

 

 

The quality of a crystal is not exactly measurable. However we can compare measurements on several physical properties to standards for clean and regular crystals. The half-width of the rocking curve of an XRD reflection is such a property.

The quality of the crystalline lattice is determined by its regularity. Defects, dislocations and contaminations are imperfections which exist in every lattice. Other discontinuities are grain boundaries and cracks. All these features cause local strain in the surrounding lattice, that we can measure by recording the rocking curve of a reflection. Because of the reflecting beam geometry of our diffractometers, the rocking curve half-width characterizes the surface quality of the crystal.

Tools for Crystal quality evaluation