Modelling the intermediate range order in liquid trivalent-metal halides and oxides

✍ Scribed by M.P. Tosi

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 499 KB
• Volume: 83
• Category: Article
• ISSN: 0167-7322
• DOI: 10.1016/s0167-7322(99)00068-9

✦ Synopsis

Intermediate range order may be present in the liquid structure of a polyvalent metal salt. It is signalled by a sharp peak in the diffraction pattern of the melt at low wave number. This first sharp diffraction peak (FSDP) has been observed in both tetrahedrally and octahedrally co-ordlnated network formers as well as in systems where molecular dimer units pre-exist melting or are believed to form across melting. I first briefly review studies of simple microscopic models showing (i) how the FSDP grows together with a network-type structure in trichloride melts on decreasing the metal-ion radius at constant density; and (fi) how it is modified on quenching the structure of the halogen component. I then report on progress in developing polarisable-ion models, in parallel with a prior/ density functional calculations, for the structure of molecular monomers and dlmers in both neutral and ionised states, with a view to obtaining the essential input needed for classical computer simulation studies of halide and oxide melts.