The DX centre
T.N. Morgan
Semiconductor Science and Technology
Results obtained on mixed crystals of Rb1-x(NH4)xH2PO4 are reported. These polar materials of the KH2PO4 family are characterized by a high-temperature disordered network of 0-H-0 bonds. On cooling, different orderings of these bonds correspond to th onset of a ferroelectric polarization parallel to the tetragonal c-axis in RbH2PO4 (x=O), or of antiferroelectric moments perpendicular to it in NH4H2PO4 (x=l). In the mixed crystals of interest, these transitions are suppressed by random NH4 substitutions. The NH4+ ions form H-bonds with nearby PO4 tetrahedra, occupying 0-sites and frustrating the low-temperature acid-proton order. Glass behavior results over a broad range of concentration 0.22 < x < 0.8.1,2. © 1984, Taylor & Francis Group, LLC. All rights reserved.
T.N. Morgan
Semiconductor Science and Technology
J.V. Harzer, B. Hillebrands, et al.
Journal of Magnetism and Magnetic Materials
O.F. Schirmer, K.W. Blazey, et al.
Physical Review B
D.D. Awschalom, J.-M. Halbout
Journal of Magnetism and Magnetic Materials