MEMS1054_week4_6v3shorter-crystaldiffraction1

What are the implications of braggs law on i geometry

This preview shows 5 out of 8 pages.

diffraction from crystals? What are the implications of Bragg’s Law on i) geometry of diffraction? ii) Diffraction experiments and diffraction data (patterns)? How do we interpret diffraction patterns? Powder Diffraction vis-à-vis single crystal diffraction? Diffraction Methods…
Image of page 5

Subscribe to view the full document.

Figure – X-ray Emission from Molybdenum Metal Using 35,000 V Electron Source (Reference (1)) White radiation , the continuous background, refers to the “Bremsstrahlung”, a continuous wavelength spectrum of X-rays with the minimum wavelength (~0.035nm) equal to 35keV. Characteristic radiation results from atomic electron transitions that are of specific energy (wavelength) and characteristic for a given element, e.g different K-alpha wavelengths for X- radiation from Cu and Cr for instance. X-rays are generated by bombardment of a metal (target) or source with high energy electrons. The continuous deceleration of which results in emission of a continuous spectrum of X-rays (Brehmsstrahlung, Figure 16)
Image of page 6
Bragg`s Law of X-ray Reflection (after Guy & Hren) 1. X-rays are scattered by periodically arranged atom sheets, leading to diffraction phenomena, including constructive and destructive interference of the scattered X-ray waves. The resulting diffracted beams appear as if the incident X-rays had been“reflected” from planes of atoms that are separated by a distance of d hkl at an angle of incidence Θ . 2. The geometric condition for constructive interference is given by the Bragg Law. It states that constructive interference occurs if the difference in X-ray travel (path) distance between those X- rays scattered by atoms in adjacent planes of the “reflecting”
Image of page 7

Subscribe to view the full document.

Image of page 8
You've reached the end of this preview.
  • Fall '10
  • Wiezorek
  • Diffraction, x-ray diffraction, Bragg Law

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern