Materials research is the underlying goal for many of the investigations at the ESRF. Contributions to this topic are thus covered in almost all of the chapters. Here we present a few examples of structural studies of materials, which do not easily fit into other sections. 

In most cases, the highlights of this year deal with time-resolved studies, non-ambient conditions such as extreme temperatures or high pressures, or high-resolution mapping of stresses or strains even for in situ situations such as deformation. All of these studies illustrate the use of the unique X-ray features of the ESRF such as high flux, high energies and excellent focussing capabilities, of importance for materials science.

The exploration of new synthetic methods is presented by the ordered growth of nanotubes in a framework of (ALPO4-5) single crystals as monitored by X-ray diffraction. Another example is the growth at high temperatures and high pressures of large superconducting mercury cuprate single crystals in a large volume press.

High pressure and high temperatures also feature prominently in a study of the MgO-FeO systems at pressures and temperatures mimicking the conditions at the earth's mantle. These studies give information about the dynamics in this part of the earth. Lithium metal, in one study, is subjected to high pressure showing that lithium undergoes a sequence of structural phase transitions and even becomes a semiconductor at high pressures. Valuable information concerning the physics and chemistry of dense sp-band metals was obtained. Diffraction methods were employed in both cases.

Local structure rearrangements have been studied in several experiments. Time-resolved studies of undercooled liquid Ge give new information on liquid structures and metastable phases. Grain growth in nanocrystalline Fe, of importance for nanofabrication, has been studied as a function of temperatures and annealing time. Temperature and composition variation studies of the Co-Cu system have given interesting information of the mechanisms of giant magnetoresistance. It was concluded that the growth of a magnetic particle embedded in a non-magnetic phase with sharp boundaries is ideal for large magnetoresistance.

Two studies illustrate strain/stress investigations. Stress and strain fields play a fundamental role in processing of materials. One contribution presents the use of high-energy X-rays to perform complete strain mapping in bulk materials with measuring gauges down to ~100 µm3. High acquisition rates were achieved enabling in situ profiling of complete strain tensors, separation of macro- and intergranular strains and texture. The novel technique of friction stir-welding, by which "difficult" metals can be welded using extreme heat, is of interest to the aeronautical and automotive industries. Detailed residual-stress profiles over a friction stir weld in a 6 mm-thick aluminum alloy plate are presented.

Quasicrystals of AlPdMn were studied by hard X-ray holography. The surroundings of the Mn atom in this compound could be imaged holographically. This method may well help in the understanding of quasicrystals. Mapping of average 3-D decorations in these compounds may also be possible.