It is really amazing that quartz has attracted the attention of scientists for more than a century, revealing a fascinating variety of new interesting phenomena. Recent findings by a team from UJF in collaboration with the ESRF (long period incommensurate acoustic modulations, and universal twisting of natural quartz minerals) are at the center of a collaboration between our-group-visitor M.Walker and E.Kats with G.Dolino of UJF.

The "freezing on heating" of liquid solutions has been recently observed by a ILL-UJF team. This is a counterintuitive reversible liquid-solid transition taking place upon heating and it has been rationalized and modelled by our group visitors (H.P. Trommsdor and A. Hueller in collaboration with M. Johnson).

Phase diagrams of methane and deuterated methanes under pressure exhibit a low-temperature phase whose orientational structure has not been determined, in spite of almost 40 years of research-effort. Recently W. Press and M. Neumann have solved the structure, but inelastic neutron scattering experiments on CD3H have revealed a complicated spectrum which needs to be interpreted (A .Hueller with ILL/UJF experimentalists and Computing for Science group).

Vibrational modes in quasicrystals have been analyzed and interpreted in the framework of phenomenological and microscopic theoretical models, which allow all inelastic-scattering features of the vibrational spectra to be described qualitatively and quantitatively (E. Kats with ILL/UJF experimentalists, PRB, 2004, J. of Phys.: Cond. Mat., 2005).