Research at the Laboratory of Crystallography

Research at the laboratory of crystallography aims at establishing relationships between crystal structure and physical properties, as well as at providing the structural basics for the understanding of phase transitions. The Research is concentrated on aperiodic crystals, including phase transitions between incommensurate, periodic and partially ordered structures. The second topic of interest is accurate charge-density studies by the Maximum Entropy Method for both periodic and aperiodic crystals. Experimental methods at the Laboratory of Crystallography include single-crystal x-ray diffraction and x-ray powder diffraction (Equipment). Both techniques can be combined with low- and high temperature attachments and they can be performed at high pressures. X-ray scattering is also performed with synchrotron radiation at Hasylab (Hamburg), ESRF (Grenoble), and NSLS (Brookhaven - USA).

A selection of specific projects: 

• Maximum Entropy Method (MEM)
• Low-dimensional magnetic materials
• Charge-density-wave compounds
• Materials physics
  

Case Studies:

• 2011: Chemical bonding in boron from the experimental charge density of ɤ-B₂₈
• 2010: Commensurate charge-density wave in SmNiC₂ at T = 60 K rendered incommensurate by frustration
• 2005: Incommensurate magnetic order in the spin-Peierls compounds TiOBr and TiOCl
• 2004: Charge-density wave transitions in Er₅Ir₄Si₁₀
• 2002: Incommensurately modulated Sr₂Nb₂O₇
• 2001: Crystal structures of Nb₃Te₄ at high pressures
• 2001: Two-dimensional charge-density wave in (PO₂)₄(WO₃)₈
• 2001: Structure of the charge-density wave in(TaSe₄)₂I
• 2000: Charge-Order in NaV₂O₅