For this we first need to think on what different phenomena come into picture when we allow x-rays to fall on a sample at very small angles.
1. At small angles together with the diffraction, reflection of x-rays from the sample surface also took place. This reflection property is used to analyse the surface properties of the material like surface roughness. You can search XRR for more information. XRR is used to determine the layer or bilayer thickness, surface or interface roughness, and density of the film.
2. As one of the parameter responsible for getting a good peak intensity is interaction volume. In very thin films (grown over the substrate at atomic level, due to very low interaction volume normal XRD will not give any peak. But at lower angle (grazing incident) increased interaction give sufficient peak to carryout XRD analysis.
For this we first need to think on what different phenomena come into picture when we allow x-rays to fall on a sample at very small angles.
1. At small angles together with the diffraction, reflection of x-rays from the sample surface also took place. This reflection property is used to analyse the surface properties of the material like surface roughness. You can search XRR for more information. XRR is used to determine the layer or bilayer thickness, surface or interface roughness, and density of the film.
2. As one of the parameter responsible for getting a good peak intensity is interaction volume. In very thin films (grown over the substrate at atomic level, due to very low interaction volume normal XRD will not give any peak. But at lower angle (grazing incident) increased interaction give sufficient peak to carryout XRD analysis.