Evidence for a continuous s-d transition in FCC caesium at high pressure

Abstract

Neutron diffraction measurements up to 43 kbar at 298K show that the volume of FCC Cs is smaller than expected from a comparison with the BCC phase, with other alkali metals at high pressure and with transition metals. This is attributed to a continuous s-d transition of the conduction electron character which causes a lowering of the average kinetic energy of the conduction electrons.