Investigation of order–disorder transition in BICUVOX single crystals
Piotr Kurek , P. Pongratz , M.W. Breiter
AbstractSingle crystals of nominal composition Bi2V0.9Cu0.1O5.35 were obtained by growth from the melt. DTA curves exhibit effects due to phase transitions, one endothermic effect during heating and one exothermic during cooling. Electron diffraction experiments combined with in-situ heating were done by TEM. Evidence was found that superlattice spots present on diffraction patterns in the low temperature range vanish for temperatures higher than 720 K. During cooling the superlattice spots reappear reversibly. The impedance of the crystals was measured in the direction parallel to the layers of the intergrowth structure. An Arrhenius-type dependence of conductivity with two activation energies different for the low and high temperature regions was observed. The transition temperatures observed in DTA coincide with those observed in electron diffraction experiments and correspond to the slope changes in the Arrhenius plots. A phase transition, involving an order–disorder process of oxygen ions, is considered responsible for this phenomenon.
|Journal series||Solid State Ionics, ISSN 0167-2738|
|Keywords in English||BICUVOX, Oxide ion conductor, Phase transition, Single crystal, Superlattice|
|Publication indicators||: 2006 = 2.19 (2) - 2007=2.228 (5)|
|Citation count*||11 (2015-06-29)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.