Microscopic Observations of Phase Transitions in CsPbCl₃

Abstract

It is shown that the Householder method can be considered as a Lanczos method, with the same properties for the convergence of the eigenvalues. An application to a proton two-particle-neutron two-hole shell-model calculation in '32Te is carried out. Moreover, in the specific case of tke J" = 2' level, the convergence properties for both methods are studied in detail.

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

“…Until now, only incomplete results on this structure have been published (Moller, 1957;Hirotsu, 1971 ;Cohen, Young, Chang & Brower, 1971 ;Imaoka, Modorikawa, Ishibashi & Takagi, 1972;Pozdnyakova, 1975).…”

“…We are concerned here with the experimental investigation of this structure, which appears as rather complicated; this is because the important loss of symmetry between the prototype high-temperature non-ferroelastic phase (point group m3m) and the monoclinic ferroelastic phase (point group 2/m) allows eight permissible domain pairs and fourteen kinds of walls. Until now, only incomplete results on this structure have been published (Moller, 1957;Hirotsu, 1971 ;Cohen, Young, Chang & Brower, 1971 ;Imaoka, Modorikawa, Ishibashi & Takagi, 1972;Pozdnyakova, 1975).…”

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

“…No systematic investigation of the ferroelastic domain structure has been performed; only a few results appear in the literature (Meller, 1957;Hirotsu, 1971;Cohen, Young, Chang & Brower, 1971;Imaoka, Modorikawa, Ishibashi & Takagi, 1972). The loss of most of the symmetry elements of the cubic prototypic phase gives rise to a very complicated domain structure in the room-temperature monoclinic phase.…”