Structural and ionic transport properties of some A2BX4 (A=Cu, B=Pb, Sn, X=Br, I) compounds.
Solid State Ionics, Volume 44, No 1–2, Pg:99–105
The compounds Cu2PbBr4, Cu2SnI4, and Cu2PbI4 have been synthesized as stable phases in the CuBr-PbBr2, CuI-SnI2, or CuI-PbI2 binary systems. Cu2PbBr4 is cubic (a0=9.170 A ̊), whereas Cu2SnI4 and Cu2PbI4 are hexagonal with a=9.050, c =9.706 A ̊, and a=8.064, c=15.128 A ̊, respectively. These materials are characterized mainly by a rather high anionic defect conductivity over the temperature range 20-270°C. The activation energy for the ionic defect mobility is 0.27 eV for Cu2PbBr4, 0.28 eV for Cu2SnI4 and 0.31 eV for Cu2PbI4