X-RAY Diffraction & Reflectometry (XRD and XRR) SERVICES
Covalent offers both X-ray diffraction analysis and X-ray reflectometry services to determine phases and crystal structures of samples.
X-ray diffractometry (XRD analysis) is key to determine phases and crystal structure of samples. It is a foundational technique for any material development, including advanced materials and thin films. An X-ray beam strikes the sample and the light is diffracted by the crystalline pattern. An interference pattern is then created that is observed by a detector. The pattern observed is specific to each crystalline phase and for a material containing several phases—the patterns add up. This means observing these diffraction patterns gives a fingerprint that can, in theory, be analyzed to reverse-engineer the phases and composition of the sample.
In X-ray reflectometry (XRR analysis), the instrument reflects a beam of X-rays on a flat surface and measures the intensity of X-rays reflected in the specular direction (reflected angle equal to incident angle). If the interface is not perfectly sharp and smooth, then the reflected intensity will deviate from that predicted by the law of Fresnel reflectivity. The deviations of the X-ray reflectometry can then be analyzed to obtain the density profile of the interface normal to the surface. This technique gives valuable information on a thin film’s thickness, density, roughness, and interstitial roughness. Although modern software helps with the interpretation of the XRD/XRR data, strong expertise is needed in many cases to make out noise from signal and to extract meaning from patterns altered by defects in the crystalline structures, or by stress.
If you have questions about XRD or XRR testing and analysis, contact our team.
APPLICATIONS OF XRD AND XRR:
Companies developing and commercializing advanced materials, thin films, semiconductors, optical components, and coatings are frequent users of X-ray reflectometry and X-ray diffraction services.
MEASUREMENTS TAKEN USING XRD AND XRR:
- Identification and quantification of crystalline phases
- Crystal structures and lattice parameters
- Residual stress quantification
- Preferred orientation (texture)
- Film thickness, density, and interfacial roughness
USES & LIMITATIONS OF XRD AND XRR:
- What it is great for:
- Quantitative measurement of phase and texture orientation
- Works on powders, films, and bulk materials
- XRD has limited capabilities with respect to amorphous materials while XRR does not.
- Elemental composition of materials should be known
Rigaku SmartLab: The SmartLab is a state of the art, high-resolution tool with a heated stage by Anton Paar (room temp to 1100°C). The SmartLab works with powders, thin films, epitaxial films and single crystals, and has multiple optical configurations such as Parallel Beam, Bragg-Brentano, Grazing Incidence, In-Plane and High Resolution.
SmartLab Studio II Software: The newest software package from Rigaku synergistically integrates measurement and analyses methods for routine and advanced XRD and XRR techniques. The XRR and High-Resolution XRD modules, in particular, are known to be some of the best available, producing very high-quality results in even less time.