STRUCTURE AND PROPERTIES OF BA2MG3SI4, A ZINTL PHASE WITH PLANAR SI-6UNITS

Within the scope of the investigations on the phase system Ba/Mg/Si a new ternary Zintl phase of the composition Ba2Mg3Si4 was found and str ucturally characterized. The silicon substructure is built up of Sit p airs and a new type of Zintl anion, a planar Sib chain. Temperature de pendent measurements of the electric conductivity and the magnetic sus ceptibility show a metallic behavior. Accompanying quantumchemical inv estigations on the base of the LMTO-ASA method confirm these results a nd allow an insight in the present bond situation.