Experiment using the Disc Chopper Spectrometer

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Experiment using the Disc Chopper Spectrometer

• Rotational Ligand Dynamics
• Group D
• S. Diallo, I-K. Jeong, S. Jonas, D. Phelan, Y.
  Liu, V. Atakan, H. Wu

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Our system MnN(CN)22.pyrazine

• . At 408 K
• - Large Debye-Waller Factor on pyrazine
• -Phase transition
• At 435 K Decomposes and loses pyrazine

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Experiment

• The goal is to probe the motion of the Hydrogen
  atoms in MnN(CN)22.pyrazine.

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DCS TOF instrument
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Measurement and Data Analysis

• Deuterated sample for coherent Bragg diffraction
  to obtain structure as a function of temperature
  and paramagnetic structure
• Protonated to observe both single particle motion
  (quasielastic) and to weigh the inelastic
  scattering spectrum in favor of hydrogen
  (vibrations)

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Protonated Data fitting using DAVE

• Ao ½1sin(2Qr)/(2Qr)

At T 425 K
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Elastic Incoherent Scattering Function (EISF)

• T425K, Fitting of EISF, Eq p0 p1
  sin(p2x)/(p2x)

Rp23.86(3)A
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Conclusions and further considerations

• In our fitting, we did find a good value of the
  rotation radius using the two-fold
  model.

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Thanks to all the NCNR staff for their help and
support.