AB initio molecular dynamics simulations of liquid alloys: netowrk formation, structure factors and electrical conductivity of NASN alloys

摘要

Many lqiuid alloys, in particular, the alkali-group IV alloys, exhibit (Zintl) anion clustering and show strong effects of compound formation. A typcial example of such Zintl systems are sodium-tin alloys. In the solid NaSn crystal the Zintl anions Sn~4_4- appear (1). An interesting question is the stability of these anions in the liuqid. Furthermore, the electrical conductivity of these alloys shows a strong dependence on composition (2): For the limiting (sodium-rich or tin-rich) cases a metallic (small) conductivity appears, but for the nearly equimolar compositions a semi-metallic behavior -with a considerably smaller conductivity-is observed.