Order–disorder phenomena in layered CuCrSe2 crystals

• DOI: 10.1016/j.matchemphys.2014.03.024
• Publication Date: 2014-04-06T01:16:28Z
• Authors: A. Gagor; D. Gnida; A. Pietraszko
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract The thermal motion of Cu + ions in a quasi-two dimensional copper ion conductor CuCrSe 2 is studied in the vicinity of the order-disorder phase transition to superionic phase, basing on a single-crystal and powder X-ray diffraction, specific heat and electrical resistivity measurements. The copper ions gradually migrate with temperature decrease to empty tetrahedral sites reaching occupancy equilibrium in the disordered high-temperature phase at T s = 365 K. The copper migration between Cuα and Cuβ tetrahedral sites occurs through the neighboring, face-sharing octahedral holes. Disorder of Cu + ions brings perturbations in periodic potential of the crystal lattice providing additional scattering centers for electrons.