A study of orientational disorder in NaCl-type phase I of ND4I by reverse Monte Carlo and maximum entropy methods

摘要

Structure and orientational disorder of ammonium ions in the high-temperature phase I of ND4I were studied by reverse Monte Carlo and maximum entropy methods using powder neutron diffraction data. The ammonium ions were found to perform a librational motion with an average angular libration amplitude of gamma = 20 degrees and reorientational motion by 39 degrees jumps of the N-D bonds between (x x x) and (x x z) positions in the structure. Reorientations by 90 degrees jumps were found to have a low probability. (C) 2001 Elsevier Science B.V. All rights reserved. [References: 28]