Theoretical investigation of the ferroelastic domain structure in cesium lead chloride in the monoclinic phase

Abstract

The ferroelastic domain structure of CsPbCl3, in its monoclinic phase, is analyzed by two theories: group symmetry and tensor method, or twinning by pseudo‐symmetry. The loss of symmetry between the prototypic and the monoclinic phases is important and allows the existence of twelve kinds of domains. Theories provide a coherent description of domain pairs and a determination of the position of W and S walls.

Experiment investigation of the ferroelastic domain structure in cesium lead chloride in the monoclinic phase

“…In the association D:-D4, the domain D4, limited by $14 or S]4 walls, appears as a wedge in the domain D a, the edge of which is parallel to the z axis, and the aperture angle is 20°12 ' (see equations for $14 and S'14 in Table 3, Chabin, 1980). This association is only observable in the plane xy'.…”

“…The orientation of the wall with respect to the observation plane is determined by its equation (Chabin & Gilletta, 1980). Two kinds of observable walls are obtained which are described below.…”

“…Its domain structure in the monoclinic phase has been theoretically investigated in a preceding paper (Chabin & Gilletta, 1980), in which we applied to CsPbCI3 the group analysis method (Janovec, 1972), the strain tensor method (Sapriel, 1975) and the pseudosymmetry twinning method (Friedel, 1926;Chabin, Gilletta & Ildefonse, 1977).…”

Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

“…Chabin and Gilletta [15,16] have investigated the domain structure in CsPbCl3, theoretically and experi mentally, for the room temperature phase. Through microscopic examination they found the angle be tween twin walls to be 89°.…”

Twin Structure of (La, Nd)GaO3 Solid Solutions

“…So, La-Nd substitution must lead to change of orientation of S-type twin walls in the La 1-x Nd x GaO 3 solid solutions crystals. Orientations of the S-type twin walls in the La 1-x Nd x GaO 3 were defined by Friedel's method of the rhombic section (CHABIN and GILLETTA., 1980). The S-type twin wall contains a <111> pseudo-symmetry twofold axis and an intersection of two planes: the orthorhombic lattice plane {112} almost perpendicular to the considered twofold axis <111> and the plane that is exactly perpendicular to this axis.…”