LITHIUM SODIUM SILICIDE Li3NaSi6 AND THE FORMATION OF ALLO-SILICON.

Article abstract of DOI:10.1016/0022-5088(88)90095-1

Metallic grey Li//3NaSi//6 is formed by heating the elements in stoichiometric amounts. The compound is the only stable ternary phase in the Li-Na-Si system, and does not belong to the tetrasilatetrahedrane derivatives. The novel complex layer structure is characterized by two-dimensional infinite polyanions showing polymerized tube-like structural units which are known from Hittorf's violet phosphorus and GeAs//2 respectively. The alkali metal atoms are inserted between the respective polyanionic layers Li//3NaSi//6 is a diamagnetic semiconductor with a molar susceptibility chi //m//o//l of minus 243 multiplied by 10** minus **6 emu mol** minus **1, R(300 K) equals 50 OMEGA and R(2 K) equals 3 multiplied by 10**3 OMEGA . Li//3NaSi//6 reacts with protic solvents as well as with benzophenone (in tetrahydrofuran) topotactically yielding a new metastable silicon modification, namely allo-Si.