Symmetry and phase transitions in (AsO4) 2H2 (U02) 2. 8 H20.

Abstract

Some reasonabíe guesses on the point group symmetry of the paraelectric, antiferroelectric and ferroelectric phases of synthetic hydrogen uranospinite have been made, taking as starting points the previously known facts and macroscopic symmetry considerations. The most probable point group for the paraelectric phase is 4/m m m , for the anti ferroelectric phase II most probable point groups are 1, 1, 2 and 222, for the ferroelectric phase III is I and for the forced ferroelectric phase IV, 4m mm , Some mechanisms are proposed to explain the structural features observed.