HIGH-RESOLUTION NEUTRON POWDER DIFFRACTION STUDY OF ICE Ic

W. Kuhs , D. Bliss , J. Finney

High-resolution neutron powder diffraction data on deuterated cubic ice (ice Ic) prepared by transforming recovered ice II have been obtained. Structure refinements in the cubic spacegroup Fd3m were performed. The hydrogen atoms are fully disordered and the interatomic distances are found to be identical with those in ice Ih. Although the general appearance of the powder pattern is cubic, several anomalies have been observed. Paticle size effects are important and from the peak broadening a mean particle size of 160(30) Å was calculated. Some Bragg peaks show additional broadening or distinct skewness on the high- or low-angle side indicating the existence of deformation faults in the stacking sequence. The presence of at least one non-cubic Bragg peak, which can be indexed as 100 in the lattice of ice Ih, is explained in terms of hexagonal sequences in the stacking.

Domaines: Articles anciens

W. Kuhs, D. Bliss, J. Finney. HIGH-RESOLUTION NEUTRON POWDER DIFFRACTION STUDY OF ICE Ic. Journal de Physique Colloques, 1987, 48 (C1), pp.C1-631-C1-636. ⟨10.1051/jphyscol:1987187⟩. ⟨jpa-00226453⟩