1 / 20

Scattering Techniques

Scattering Techniques. Lecture 17 G.J. Mankey gmankey@mint.ua.edu. Elastic-no energy loss. Light Reflectometry Ellipsometry* X-rays Diffraction* Reflectometry Electrons Diffraction* Neutrons Diffraction Small Angle Neutron Scattering* Reflectometry*.

antranig
Download Presentation

Scattering Techniques

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Scattering Techniques Lecture 17 G.J. Mankey gmankey@mint.ua.edu

  2. Elastic-no energy loss. Light Reflectometry Ellipsometry* X-rays Diffraction* Reflectometry Electrons Diffraction* Neutrons Diffraction Small Angle Neutron Scattering* Reflectometry* Inelastic-energy loss to excitation. Light Raman* Brillouin* X-rays EXAFS* Electrons HREELS* Ion Scattering* Neutrons Inelastic Neutron Scattering Scattering

  3. Inelastic Light Scattering • Brilloin Scattering-Scattering from an acoustic phonon. • Raman Scattering-Scattering from an optical phonon.

  4. EXAFS • Fine structure in the vicinity of the adsorption edges contains information about the local environment of the chemical species. ref: Prof. Brian Tonner, UCF

  5. X-Ray Absorption • Photon energy is tuned to elemental core level. • Technique probes chemical composition. • Requires a synchrotron x-ray source and monochromator. ref: Prof. Brian Tonner, UCF

  6. X-Ray Adsorption Measurements • Each method of measurement has advantages specific to the detection method. ref: Prof. Brian Tonner, UCF

  7. The electron probing depth follows the "Universal Curve." This is also true for electron spectroscopies. The curve has the form: Where A and B are material dependent parameters. To first approximation, A and B are the same for all metals. Electron Inelastic Mean Free Path ref: Prof. Brian Tonner, UCF

  8. Information in XAS • The range of energy losses probed give different information about the local environment of the chemical species with the particular adsorption edge. ref: Prof. Brian Tonner, UCF

  9. HREELS Ref: http://nano.kaist.ac.kr/2002ch607/Ch5-VIb.pdf

  10. Electron Scattering Mechanism Ref: http://nano.kaist.ac.kr/2002ch607/Ch5-VIb.pdf

  11. HREELS Example Ref: http://nano.kaist.ac.kr/2002ch607/Ch5-VIb.pdf

  12. Ion Scattering Spectroscopy Ref: http://nano.kaist.ac.kr/2002ch607/Ch5-VIb.pdf

  13. Properties of Neutrons ref: SNS Website

  14. Neutron Scattering ref: T.E. Mason

  15. Reciprocal Space ref: T.E. Mason

  16. Small Angle Neutron Scattering • Neutrons probe length scales comparable to TEM and soft x-rays. • Neutrons are a gentle probe since their energies are of the order of a few milli electron volts as opposed to hundreds to thousands of electron volts for x-rays and electrons. ref: Charles Glinka, NIST

  17. Contrast • The contrast mechanism for neutrons scattering length density rather than electron density for x-rays. ref: T.E. Mason

  18. SANS Instrumentation • Nanoscale lengths are probed. ref: Charles Glinka, NIST

  19. Neutrons Probe Magnetic Structure • The magnetic scattering length in Fe is 1/3 of the chemical scattering length, so SANS also probes magnetic structures. ref: Charles Glinka, NIST

  20. Neutron Reflectometry • Q-dependent reflectivity gives interfacial roughness and correlation length. • Polarized reflectometry yields magnetic roughness. ref: T.E. Mason

More Related