Atomic structure at the nanoscale a 21st century materials challenge

Page
6

Fraction of the sample that is dimerized has been mapped out through the hysteretic phase transition

2. Cr-doping: NO: the local dimers are destroyed

3. x-ray irradiation: YES: the local dimers survive

98keV x-rays also melt the long range order but the melting is faster than previous reports

Long range order recovers quickly at 100K as previously observed

Total Scattering Approach:

Crystallography – sensitive to long range order dimers

Atomic PDF – sensitive to presence of dimers

Dimer peaks clearly resolved and visible

HIGHLIGHT

Slide 43

Acknowledgements

People:

Simon Billinge

(Columbia/BNL)

Adam DeConinck

(MSU)

Pavol Juhas

(Columbia)

Xiangyun Qiu

(MSU, now at NIH)

Marek Schmidt

(MSU/ISIS, now at Polish Academy of Sciences)

Hyunjeong Kim

(LANSCE)

Ahmad Masadeh

(MSU, now at University of Jordan)

Gianluca Paglia

(MSU, now in industry, Australia)

Thomas Proffen

(LANSCE, Los Alamos)

John Mitchell

(MSD, Argonne)

Tapan Chatterji

(ILL, Grenoble, FR)

Paolo Radaelli

(ISIS, UK)

Peter Chupas, Douglas Robinson

(APS, Argonne)

Facilities:

Advanced Photon Source, Argonne

Intense Pulsed Neutron Source, Argonne

Los Alamos Neutron Scattering Center

ISIS, Rutherford Appleton Laboratory

Funding:

NSF DMR 0304349,

DOE DE-AC02-06CH11375,

DOE DE-AC52-06NA25396,

DOE DE-AC02-98CH10886.

Slide 44

Thank you!