As Weird as They Come: Elemental Metals at High Pressure

At ordinary conditions of pressure and temperature, most elemental metals crystalise in simple, high-symmetry, densely-packed crystal structures. Until some 15 years ago, all elemental crystals were assumed to adopt simple close-packed crystal structures at extreme compression, and little of interest was expected to happen at intermediate pressures.

This expectation has proved to be spectacularly wrong. Numerous elements across the periodic table are now known to adopt very complex crystal structures at high pressure, the archetypal simple metals lithium and sodium have been reported to become semiconductors in the megabar pressure range, and the heavier alkali metals have been predicted to become ferromagnetic under pressure. I will present an overview of experimental and computational research that has led to a dramatic change of our understanding of the structural and physical properties of elemental metals at high pressure.

Tea and doughnuts from 16.30.