Novel Features ofSr1−xCaxTiO3

Abstract

Structural and dielectric evidences are advanced to show that the Sr1-xCaxTiO3 (SCT) system undergoes an antiferroelectric (AFE) phase transition in the composition range 0.18</=x</=0.40. Stabilization of the AFE phase, instead of the ferroelectric (FE) phase known for 0<x<0.12, is shown to be intimately linked with the nonpolar antiferrodistortive phase transitions driven by the R and M point instabilities preceding the AFE transition. It is proposed that the disorder and frustration introduced by CaTiO3 substitution in the incipient FE matrix of SrTiO3 leads to the smearing of the varepsilon(')(T) response in SCT for 0.002<x<0.12 akin to dipole glasses and relaxor ferroelectrics.

Interplay between antiferrodistortive, ferroelectric, and superconducting instabilities inSr1−xCaxTiO3−Lima1, Luz2, Oliveira3 et al. 2015Phys. Rev. B323430View full textAdd to dashboardCite

“…We notice that this result is in agreement with the phase diagram drawn by Ranjan [31] scrutinizing a number of previous reports by other authors.…”

Complex antipolar2×4×22structure withPnmasymmetry inProsandeev1, Khalyavin2, Raevski3 et al. 2014Phys. Rev. B201120View full textAdd to dashboardCite

“…The latter two calculations were done for √ 2 × √ 2 × 4 and even longer supercells, along axis c, for example √ 2 × √ 2 × 6, which are consistent with recently found long rotational patterns in NaNbO 3 [11]. A complex twin structure is expected at morphotrophic phase boundaries of some solid solutions [12,13]. It has been realized recently that the common mechanism for the formation of such a complex twinned structure can be explained by flexoelectric interactions [14,15].…”

Elastic and anelastic anomalies in (Ca,Sr)TiO3 perovskites: Analogue behaviour for silicate perovskites

“…A recently proposed phase diagram is reproduced in Figure 1, after Carpenter et al (2006a). For Ca-rich compositions, the sequence of transitions with falling temperature is Pandey, 1999, 2001a;Ranjan et al, 2000;Mishra et al, 2001;Ouillon et al, 2002;Ranson et al, 2005;Mishra et al, 2005Mishra et al, , 2006a, and there has been a further suggestion of monoclinic symmetry (Woodward et al, 2006). From an earth sciences perspective, the CST solid solution has…”