Structure and electrical properties of crystalline and glassy Ag2PbP2O7

• Published in: Materials letters 2001-02, Vol.47 (4-5), p.212-218
• Main Authors: DRIDI, N, BOUKHARI, A, REAU, J. M, ARBIB, E, HOLT, E. M
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Diffusion in solids; Disordered solids; Exact sciences and technology; Glasses; Inorganic compounds; Physics; Salts; Self-diffusion and ionic conduction in nonmetals; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Transport properties of condensed matter (nonelectronic)
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(00)00237-8

Single crystals of Ag2PbP2O7 were prepared by melting of the crystalline phase under phosphate flux. Ag2PbP2O7, isotype of Na2PbP2O7, is of triclinic symmetry with the space group P(-1) (Z = 2). The unit cell parameters are: a = 0.5502(6) nm, b = 0.7008(8) nm, c = 1.0018(9) nm, alpha = 106.63(6) degrees, beta = 93.89(7) degrees, gamma = 110.68(6) degrees. The lattice of Ag2PbP2O7 consists of corner-shared structural units {Pb2P4O14}4-, which form ribbons parallel to the [010] direction. The {Pb2P4O14}4- units result from the association of corner-shared PbO5 polyhedra and P2O7 pyrophosphate groups. The ribbons are interconnected by PbO-O-P bridges in the [100] direction and form lamina parallel to (001) plane. Silver atoms are located between two alternating lamina. Glasses with the same composition as the crystalline phase were synthesised. A study of transport properties of Ag2PbP2O7 in the crystalline and glassy forms is reported. 26 refs.