Synthesis and characterization of novel chalcophosphate materials.

摘要

Metal chalcophosphate compounds have received significant attention due to the presence of some industrially relevant physical properties such as spontaneous ferroelectric ordering,1-3 reversible phase changes,4 nonlinear optical properties,5 and photoconductivity.6 These compounds contain a chalcogenide (Q = S, Se, or Te) that is directly bonded to oxidized phosphorous to form various [PxQy]z- anions. The identity and relative concentration of the metal ion has a dominant effect on the structure and properties of the resultant compound, and is not simply a requirement for charge balance.;In this work, several novel chalcophosphate materials are presented, and some insights are provided into the nature of the molten reactions that form them. The novel compounds have the general formula MM'[PxQ y] where M = Cu, Ag,2 Tl,7 K8, or Cs,9 M' = Bi or Hg, and Q = S, or Se. The synthetic conditions required to produce each compound are detailed and so are the structural features of the crystallographic refinement. These crystalline compounds are also characterized by other spectroscopic techniques including Uv/vis and Raman, thermal analysis, and electronic structure calculations.;The reactions to produce these compounds were characterized by high temperature nuclear magnetic resonance, and from these data, the presence of a significant quantity of free radicals in the melts and syntheses of chalcophosphate-containing materials is demonstrated. Additionally, the melt was found to have relatively low viscosity, and there was evidence that the species that exist in the molten liquid have small (several A) radii and may be related to the species that are observed in the room temperature crystalline compounds.;1. Bourdon, X.; Maisonneuve, V.; Cajipe, V. B.; Payen, C.; Fischer, J. E. J. Alloys Compd. 1999, 283, 122-127. 2. Gave, M.; Bilc, D.; Mahanti, S.; Breshears, J.; Kanatzidis, M. Inorg. Chem. 2005, 5293-5303. 3. Maisonneuve, V.; Cajipe, V. B.; Simon, A.; VonDerMuhll, R.; Rayez, J. Phys. Rev. B. 1997, 56, 10860-10868. 4. Chung, I.; Do, J.; Canlas, C. G.; Weliky, D. P.; Kanatzidis, M. G. Inorg. Chem. 2004, 43, 2762-2764. 5. Bridenbaugh, P. Mater. Res. Bull. 1973, 8, 1055-1060. 6. Galdamez, A.; Manriquez, V.; Kasaneva, J.; Avila, R. E. Mater. Res. Bull. 2003, 38, 1063-1072. 7. Gave, M.; Malliakas, C. D.; Weliky, D. P.; Kanatzidis, M. G. Inorg. Chem. 2007, 46, 3632-3644. 8. Gave, M.; Weliky, D. P.; Kanatzidis, M. G. Inorg. Chem. 2007, Accepted. 9. Gave, M.; Canlas, C.; Iyer, R. G.; Kanatzidis, M. G.; Weliky, D. P. J. Solid State Chem. 2007, 180, 2877-2884.