Classification of octahedral tilting phases in the perovskitelikeA2BX4structure

Abstract

The possible lower symmetries (subgroups) of the A2BX4 structure (space-group symmetry D4&) due to rigid octahedral tiltings at phase transitions are investigated. The method for obtaining subgroups determined by reducible representations (i.e., coupled order parameters) is described. This method depends upon subgroup information for irreducible representations (i.e. , single uncoupled order parameters). All subgroup symmetries which are allowed by the coupling of two simple octahedral tiltings are listed for this structure.

Electron microscopic study on SrGdMnO4

“…bic [5] structures, respectively. The structure relationship and phase transitions among these modifications and the archetype have been investigated and discussed in terms of the octahedral tilting system [6][7][8][9].…”

Antiferrodistortive phase transition inPb(Ti0.48Zr0.52Hatch1, Stokes2, Ranjan3 et al. 2002Phys. Rev. B8910630View full textAdd to dashboardCite

“…5,9,10 Using ISOTROPY to couple the ⌫ 4 Ϫ and R 4 ϩ IR's, we obtain three possible antiphase tilt systems that can combine with the Cm ferroelectric structure: a Ϫ a Ϫ c 0 , a Ϫ a Ϫ c Ϫ , a Ϫ b Ϫ c Ϫ , which result in space-groups Cm, Cc, P1, respectively. The tilt system we are seeking is thus a Ϫ a Ϫ c Ϫ .…”

Negative Thermal Expansion in Hybrid Improper Ferroelectric Ruddlesden-Popper Perovskites by Symmetry Trapping

“…Due to the relatively simple structure of the perovskite and perovskite related materials, classification and rationalization of their structural distortions have attracted a considerable amount of work over the past decades [8][9][10][11]. Recently it has been shown that in perovskite thin films, improper ferroelectricity may be induced via strain coupling of octahedral rotations between different perovskite heterostructure layers [12].…”