An example of an instrument used for powder XRD analysis can be seen in Figure 1. To make the comparison possible, the acquired data is scaled using the highest obtained intensity count so that the final data shows the relative intensity as a function of θ. As every species has a unique diffractogram, it can be used for identification purposes simply by comparing the one obtained for the sample to those found in databases (printed or digital). In addition to intensity data, each lattice plane is labeled using so-called Miller indices that describe its geometry. To make sure that all possible lattice planes are represented, the initial sample is ground intensively into a very fine state, after which it is placed into a mold to produce a sample of suitable size for the measurement. By presenting the intensity as a function of θ, a graph known as a diffractogram can be obtained. Since the wavelength is easily selectable, this makes it possible to measure the intensity for a specific value of d by simply adjusting the incidence angle θ. At the detector, the intensity of the reflected rays is measured. After the diffracted rays have travelled through the sample, they are reflected back through the surface and guided to the detector via another collimating lens-monochromator combination. A specific wavelength is selected using a monochromator, and guided to the sample using collimating lenses. In powder XRD, the studied sample is radiated with X-rays produced using an X-ray tube. This law shows the relation between the incidence angle θ (the angle at which the radiation is directed towards the surface), the distance between the lattice planes d and the wavelength of the radiation λ. For constructive interference to occur, the scattered rays must be in the same phase, a condition that can be expressed by Bragg’s law: 2d sin θ = nλ. Diffraction occurs most visibly in structures that are highly ordered, which explains why the method in question highly suitable for analysis of crystalline structures. These rays can interfere with one another either in a destructive or constructive manner – a phenomenon known as diffraction. When radiation of a wavelength similar to the distance between atoms reaches a solid structure, it scatters, producing a multitude of rays that continue to travel through the structure.