X-ray diffraction

Researcher: Maria Olimpia Miclăuș

Keywords: structural analysis on solids, X-ray diffraction on powders and single crystals, crystalline structure

Description

X-ray diffraction is an analytical technique used for characterizing solid materials, whether organic or inorganic, with diffraction intensities generated as a result of the interactions between X-rays and the electrons of the atoms in the lattice.

Depending on the behavior of the compounds we want to investigate, we use either powder diffraction or single crystal diffraction. The information extracted by the two diffractometric techniques is used for the structural characterization of the crystal lattice.

An important advantage of X-ray diffraction is the rapidity of obtaining information, the method is non-destructive and requires a small amount of sample.

The information extracted from X-ray powder diffractograms includes:

  • Qualitative analysis of crystalline phases: based on the fact that each crystalline phase has a specific diffractogram
  • Quantitative phase analysis: If a sample contains multiple phases, the percentage of each identified phase in the examined sample can be determined based on the number and intensity of the diffraction lines
  • Microstructural analysis: determination of crystallite sizes, lattice stresses and defect probabilities
  • Determination of the degree of crystallinity: resulting from the ratio of the area of diffraction maxima to the total area which includes both diffraction maxima and the area of halos due to the amorphous phase
  • Determination of crystalline structure from powders

In the case of single-crystal X-ray diffraction the crystal structure of the compound under investigation is obtained.

 Applications

Areas of application: research and development, optimization of industrial products, purity check and impurity detection, stability assessment under different environmental conditions, etc.

Systems:

  • organic and inorganic crystalline compounds: natural and synthetic bioactive compounds, (bio)molecular systems that can be crystallized, metal-organic structures, minerals
  • amorphous materials: polymers, biopolymers and polymer composites, graphene and graphene-based composites, glass, ceramics and their composites

Industries: pharmaceutical industry, dietary supplement industry, medical devices, chemical industry, environment/ pollution control, health – nanomedicine.

 Infrastructure

The X-ray diffraction laboratory is equipped with three diffractometers:

  • Bruker D8 Advance: is used for powder measurements; it is equipped with a Ge (111) monochromator placed in the incident beam and an ultrafast detector of the LYNXEYE type ; the diffractogram collection is performed in Bragg-Brentano geometry in reflection mode
  • Rigaku SmartLab: equipped with a 9 kW rotating anode, high resolution theta-theta goniometer, it is possible to record measurements in reflection and transmission mode. In addition to powders, measurements of thin films can also be performed with this diffractometer
  • Oxford SuperNova: it is equipped with two microsources (Cu, Mo), a high performance CCD detector, equipped with Cryojet allowing measurements in the temperature range 90÷490 K, it is used for single crystal measurements

Advantages

 INCDTIM offers R&D services based on X-ray diffraction, used independently or in combination with other complementary analytical techniques, covering almost the whole range of practical applications

 Before entering into a contractual relationship, we provide consultancy to define the client/partner’s needs as accurately as possible and, if required, we carry out preliminary tests free of charge

 The existing equipment (the three diffractometers) allows us to employ diffraction methods commonly used i practice, which are already implemented in our laboratory

 We have specialized personnel capable of covering all stages of a contractual collaboration: defining the problem to be solved, experimental design, data collection, interpretation of results and their correlation with other complementary information, if necessary.

Estimated costs

The total cost of X-ray diffraction based R&D services consists of two components:

diffractometer usage time, which includes consumables and wear and tear: 25 lei/hour

labor costs, which includes personnel and indirect costs associated with sample preparation operations, analysis and interpretation of results, preparation of the analysis/research report: negotiable, depending on the complexity of the study