Li And Na Show Resistance

摘要

Putting solids under pressure reduces the distances between their atoms, and at extremely high pressures, as electron density increases, all materials approach an ideal metal. Under pressure, then, 'simple' metals such as lithium and sodium might be expected to become increasingly better conductors. But about 10 years ago, calculations suggested that neither element responds in such a straightforward manner. Instead, it was predicted that the alkali atoms would form pairs under pressure and yield more complex structures with insulating properties. Two groups in this issue present experimental confirmation that this is the case; lithium and sodium become not more metal-like but less metal-like as pressure is applied.