X ray diffraction and applications

INTRODUCTION
INSTRUMENTATION:
-Production of X-rays
-Collimator
-Monochromator
-Detector
APPLICATIONS:
POLYMER CHARACTERIZATION
STRUCTURE OF CRYSTALS
OTHER APPLICATIONS
REFERENCES

1. . Name: Deepak.S.Pandey Er.no : 150821202003 Dept : Pharmaceutics Parul institute of pharmacy X-RAY DIFFRACTION AND THEIR APPLICATIONS

2. LIST OF CONTENT: INTRODUCTION INSTRUMENTATION: -Production of X-rays -Collimator - Monochromator -Detector APPLICATIONS REFERENCES

3. It is a novel & non destructive method of chemical analysis and a variety of x –ray techniques are available in practice. These are : X – ray Absorption X-ray diffraction X-ray Fluorescence

4. Definition The atomic planes of a crystal cause an incident beam of X-rays to interfere with one another as they leave the crystal. The phenomenon is called X-ray diffraction.

5. WHAT IS X-RAY DIFFRACTION ?

6. Bragg’s Law and Diffraction How waves reveal the atomic structure of crystals How waves reveal the atomic structure of crystals N ƛ = 2d sin θ N = integer Diffraction occurs only when Bragg’s Law is satisfied Condition for constructive interference (X-rays 1 & 2) from planes with spacing d

7. Bragg’s equation is a negative law  If Bragg’s eq. is NOT satisfied  no reflection can occur  If Bragg’s eq. is satisfied  reflection may occur Diffraction = Reinforced Coherent Scattering

8. XRD Pattern of NaCl Powder: Diffraction angle 2 θ (degrees Miller indices: The peak is due to X-ray diffraction from the {220} planes.

9. Instrumentation : Production of X-rays: X-rays are produced whenever high-speed electrons collide with a metal target.

10. Collimator: Collimator system is used for achieving a narrow beam of X-rays. X-rays are allowed to pass through collimator.

11. Monochromator : Two methods are available: 1)Filter 2)crystal monochromator Filter: A filter is a window of material that absorbs undesirable radiation but allows the radiation of required wavelength to pass. eg . zirconium filter which is used for molybdenium radiation.

12. EG: USE OF FILTER TO PRODUCE MONOCHROMATIC RADIATION

13. Crystal monochromator : It is made up of a suitable crystalline material positioned in the X-ray beam so that angle of reflecting planes satisfied the bragg’s equation for required wavelength.eg flat crystal monochromator .

14. DETECTORS: 1) Photographic methods 2) counter methods: -Geiger muller counter -Scintillation detector - Scintillation detector - propertional counter

15. Geiger muller tube counter :

16. Scintillation counter :

17. A Modern Automated X-ray Diffractometer Detector Cost: $560K to 1.6M X-ray Tube Sample stage

18. Application of X-ray diffraction: 1. Structure of Crystals The analytical applications of X-ray diffraction are numerous. The method is nondestructive and gives information on the molecular structure of the sample. Perhaps its most important use has been to measure the size of crystal planes. The patterns obtained are characteristic of the particulars compounds from which the crystal was formed.

19. a) X-ray pattern of salt A b) X-ray pattern of salt B c) X-ray pattern of a mixture of salt A and B.

20. X-ray diffraction pattern of unknown material (upper spectrum)

21. 2. Polymer Characterisation Powder method can be used to determine the degree of crystalline of the polymer. The non-crystalline portion simply scatters the X-ray beam to give a continuous background, while the crystalline portion causes diffraction lines that are not continuous.

22. 3.State of anneal in metals A property of metals than can be determined by X-ray diffraction is the state of anneal . Well-annealed metals are in well-ordered crystal form and give sharp diffraction lines . If the metal is subjected to drilling, hammering, or bending, it becomes fatigued ," that is, its crystals become broken and the X-ray pattern more diffuse.

23. 4. Particle size Determination A variety of X-ray techniques may be used to determine the size of particles or crystallites. where, v=the volume or size of an individual crystallite. V = the total volume of the specimen irradiated n = the number of spots in a diffraction ring at a Bragg angle of θ δθ =the divergence of the X-ray beam and is a function of the apparatus used. v = V . δθ . cos θ / 2n

24. Applications of Diffraction Methods to Complexes. Determination of Cis -Trans Isometrism : X-ray diffraction study has been used to make the distinction between cis and trans isomers of a complex. An interesting example is the structure of bis nickel (II) dihydrate . Nickel chloride Alkaline solution of ligand Ni( pia )2.2H2O

25. Determination of Linkage Isomerism: By X-ray studies, it becomes possible to identify linkage isomers of complexes. Sometimes knowledge of the position of hydrogen atoms is useful.

26. Miscellaneous Application Soil classification based on crystallinity X-ray diffraction can also be used to assess the weathering and degradation of natural and synthetic minerals By designed experiments, the factors responsible for the degradation can be revealed Corrosion products can be studied by this method. When metal samples are exposed to the atmosphere, they are susceptible to corrosion. Tooth enamel and dentine have been examined by x-ray diffraction.

27. Application of X-ray Absorption method Analysis : Different elements absorb the X-rays to different degrees. This property has been widely used to detect broken bones, impurities, segregations, etc. Widely used in industry and medicine.  

28. Other Applications This has been used to locate trace elements, such as barium and iodine in the body This has been used to detect below holes or the segregation of impurities such as oxides in welds and other joints. Also used to measure the volume of liquids in closed vessels or pipes without opening or breaking the vessels or pipes.

29. Application of x-ray fluorescence In Agriculture – For the determination of trace elements in plants and foods The detection of insecticides on fruit and leaves The continuous determination of phosphorus in fertilizer In medicine For determination of chloride in blood serum; For the determination of strontium in blood serum and bone tissue.

30. In mining and metallurgy Other application: The determination of additives in motor oil by determining barium, zinc , phosphorus, calcium, and chloride, and The determination of lead or sulfur in gasoline. The determination of the elements of the bearings in the used motor oil, which can be performed by X-ray fluorescence, In the rubber industry, the determination of the vulcanizing element, sulfur, can be done by X-ray fluorescence. This is a means of ensuring the production of high-quality rubber. In space technology, the analysis of new alloys and ceramics can be carried out by X-ray fluorescence.

31. References: Text book of Instrumental analysis by skoog , Holler, and crouch , 2007 Edition from pg.no 2.303 to 2.339. Pictures and diagram are taken from Google images.

32. Questions…?