INFLUENCE OF THE ISOTYPICAL A(9), A(10) AND B-11 SOLVENTS ON THE PARTIAL ATOMIC VOLUME OF TIN

Lattice parameters and macroscopic densities of the solid solutions Co (Sn), Rh(Sn), Ir(Sn), Ni(Sn), Cu(Sn), Ag(Sn) and Au(Sn) were measured in the whole range of homogeneity. The largest tin-solubility in metal s of the A(9), A(10) and B-11 groups (A(9)=Co, Rh, Ir; A(10)=Ni, Pd, P t; B-11=Cu, Ag, Au) is shown by the quasihomological 4d elements Rh, P d and Ag. The behaviour of both average atomic volume and enthalpy of formation was investigated for the binary systems A(9)-Sn, A(10)-Sn an d B-11-Sn. The partial atomic volume of tin and the partial molar enth alpy of tin were analysed for phases isotypical with the Cu and Cu3Au structures. Among tile quasihomological systems, small values of the p artial atomic volume of tin and large negative values of the partial m olar enthalpy of tin were found for the solid solutions A(9)(Sn) and A (10)(Sn) as well as for the intermetallic compounds Pd3Sn (Cu3Au type) and Pt3Sn (Cu3Au type). These indicate a strong charge transfer from tin atoms to atoms of the A(9) and A(10) groups.