Sur une nouvelle famille de clathrates minéraux isotypes des hydrates de gaz et de liquides. Interprétation des résultats obtenus

The thermal degradation of the alkali silicides and germanides of formula MeSi and MeGe (Me = Na, K, Rb, Cs) leads to intermediate phases having the clathrate structure of the gas and liquid hydrates. The alkali atoms occupy holes in a distorted silicon or germanium lattice; a radius intermediate between the ionic and metallic radii accounts for the experimental results, involving a certain localization of the peripheral s electron. This conclusion is confirmed by the magnetic and electric properties.