D9 - Hot neutron four-circle diffractometer

It is used for precise and accurate measurements of Bragg intensities up to very high momentum transfer. The resolution allows routine recording of extended data sets for the detailed study of atomic disorder and atomic thermal motions.
The short wavelength allows the study of compounds containing absorbing elements like Gd or Sm.

General themes:

• Structural phase transitions ;
• Atomic anharmonicity ;
• Structural disorder ;
• Hydrogen bonding ;
• Packing of organic molecules ;
• Magnetic structures, especially Gd ;
• Electron density studies ;
• Twinning and superlattice problems ;
• Ordering in alloys

Fundamentals of diffraction:

• Extinction effects ;
• Test of dynamical theory ;
• Thermal diffuse scattering ;
• Resonance scattering

Special use:

• atomic resolution neutron holography

Because of the short neutron wavelength very small atomic displacements can be identified, accurate to typically 0.001 Å.
D9 is equiped with a two-dimensional multidetector for a more accurate and secure data collection.