Structural relaxation in complex monatomic or binary liquids by means of coherent QENS, mode distribution analysis and van hove function analysis

Kawakita, Yukinobu  ; Kikuchi, Tatsuya*  

Elemental liquid metals such as Ge, Si, Sn, Pb, Zn, Cd, Hg, Ga and Bi show complex structure far from the hard sphere (HS) packing model. Most of them have structural anomaly that an asymmetric-shaped first peak or even a shoulder aside of the first peak exists in structure factor S(Q). Among molten salts with simple cation and anion binary constituents, AgI and CuI which have superionic solid phase have peculiar ionic dynamics in their liquid phase where cation and anion motions are asymmetric. To understand such complex features of these liquids, coherent quasi-elastic neutron scattering (QENS) is very useful tool because it involves information on time evolution of all pair correlations. Properly analyzing coherent QENS leads us to fully understanding of interatomic interactions. In this presentation, we introduce the results of superionic melt CuI and complex liquid metal Bi by the mode distribution analysis (MDA) and the approach through Van Hove function.