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X-ray powder diffractometer

X-ray powder diffractometer. X-ray powder diffractometer. radiation counter. X-ray powder diffractometer. Powder diffractometer (see Jenkins & Snyder, chap. 7). Powder diffractometer (see Jenkins & Snyder, chap. 7). Bragg-Brentano geometry. X-ray powder diffractometer.

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X-ray powder diffractometer

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  1. X-ray powder diffractometer

  2. X-ray powder diffractometer radiation counter

  3. X-ray powder diffractometer

  4. Powder diffractometer (see Jenkins & Snyder, chap. 7)

  5. Powder diffractometer (see Jenkins & Snyder, chap. 7) Bragg-Brentano geometry

  6. X-ray powder diffractometer

  7. X-ray powder diffractometer

  8. X-ray powder diffractometer

  9. X-ray powder diffractometer

  10. X-ray powder diffractometer

  11. X-ray powder diffractometer

  12. X-ray powder diffractometer

  13. X-ray powder diffractometer

  14. X-ray powder diffractometer

  15. X-ray powder diffractometer

  16. X-ray powder diffractometer

  17. X-ray powder diffractometer

  18. X-ray powder diffractometer To maintain the focusing geometry, when counter is rotated at rate of 2/min, specimen is also rotated at rate of /min /min /min

  19. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Axial divergence - axis, here, is main rotation axis - asymmetric broadening toward low 2 - negative 2 error up to 90° - positive 2 error beyond 90°

  20. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Axial divergence - axis, here, is main rotation axis

  21. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Axial divergence - axis, here is main rotation axis each section of Soller slit produces its own Debye ring from a specific region in the specimen divergence angle typically ±2.5°

  22. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Axial divergence - axis, here is main rotation axis each section of Soller slit produces its own Debye ring from a specific region in the specimen divergence angle typically ±2.5°

  23. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Flat specimen peak shifts to lower 2 & asymmetric broadening depends on beam divergence & 2, plus specimen shape

  24. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Specimen transparency

  25. Powder diffractometer Bragg-Brentano instrument - errors (see Klug & Alexander) Specimen displacement Usually largest error in expt'l data Neg. peak shift - ~0.01° 2/15displacement Asymmetric broadening toward lower 2

  26. Powder diffractometer Bragg-Brentano instrument Divergence slit choice

  27. Powder diffractometer Bragg-Brentano instrument Divergence slit choice Or, theta-compensating slit - divergence slit opens as theta increases

  28. Powder diffractometer Bragg-Brentano instrument Receiving slit choice

  29. Powder diffractometer Bragg-Brentano instrument Receiving slit choice lowers intensity - little improvement in resolution poor resolution - little improvement in intensity

  30. Powder diffractometer Bragg-Brentano instrument Receiving slit choice correct slit size ~0.15°

  31. Powder diffractometer Alignment steps

  32. Powder diffractometer Alignment steps Align to focal spot Set take-off angle

  33. Powder diffractometer Alignment steps Align to focal spot Set take-off angle Zero alignment 2:1 alignment

  34. Powder diffractometer Alignment steps Align to focal spot Set take-off angle Zero alignment 2:1 alignment

  35. Powder diffractometer Alignment steps Align to focal spot Set take-off angle Zero alignment 2:1 alignment

  36. Powder diffractometer Alignment checks Run calibration pattern - use suitable standard NIST 640c (Si)

  37. Powder diffractometer Alignment checks Run calibration pattern - use suitable standard

  38. Powder diffractometer Alignment checks Run calibration pattern - use suitable standard Watch for: Intensity loss Angle shifts Resolution loss

  39. Powder diffractometer Alignment checks

  40. Powder diffractometer Alignment check "Five fingers of quartz"

  41. Powder diffractometer Alignment check "Five fingers of quartz" Measure: position & intensity of (203)1 H1/H2

  42. Powder diffractometer Alignment checks Run calibration pattern - use suitable standard NIST 1976 (Al2O3)

  43. Powder diffractometer Alignment checks Run calibration pattern - use suitable standard

  44. Powder diffractometer Alignment checks Run calibration pattern - use suitable standard

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