Controlling superstructural ordering in the clathrate-I Ba₈M₁₆P₃₀ (M = Cu, Zn) through the formation of metal-metal bonds.

ABSTRACT: Order-disorder-order phase transitions in the clathrate-I Ba₈Cu₁₆P₃₀ were induced and controlled by aliovalent substitutions of Zn into the framework. Unaltered Ba₈Cu₁₆P₃₀ crystallizes in an ordered orthorhombic (Pbcn) clathrate-I superstructure that maintains complete segregation of metal and phosphorus atoms over 23 different crystallographic positions in the clathrate framework. The driving force for the formation of this Pbcn superstructure is the avoidance of Cu-Cu bonds. This superstructure is preserved upon aliovalent substitution of Zn for Cu in Ba₈Cu_16-x Zn _x P₃₀ with 0 < x < 1.6 (10% Zn/M_total), but vanishes at greater substit

SUBMITTER: Dolyniuk J 

PROVIDER: S-EPMC5437377 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature