Rietveld analysis of strontium titanate in the Müller state

Abstract

We report a neutron and x-ray Rietveld analysis of strontium titanate down to 1.5 K. The results do not show evidence for any supplementary structural phase transition or local frozen polar ordering. These results are a supplementary indication that at very low temperature strontium titanate should display only weak local modifications of the static tetragonal structure with no strong signature in the diffraction pattern.

Average and local structure of the Pb-free ferroelectric perovskites(Sr,Sn)TiO3and(Ba,Ca,Sn)Laurita1, Page2, Suzuki3 et al. 2015Phys. Rev. B273220View full textAdd to dashboardCite

“…BCSTO as compared to (c) calculated neutron G(r) from the average structures of BaTiO3 in space groups P m3m, P 4mm, Amm2, and R3m from Kwei et al 28 and the I4/mcm average structure phase of SrTiO3. 29 In BCSTO, the Ti-O distribution is resolved into two components at 500 and 400 K. The number of components is less clear at 300 K. An asymmetry of the first Ti-O distribution is observed in the 400 K data of SSTO, with the peak becoming more symmetric upon cooling.…”

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

“…The ST depicts a paraelectric C phase with 3 symmetry down to -168 °C, where it transforms to a T phase with 4/ symmetry that features antiferroelectricity and twin domains along {101} crystallographic planes. [369][370][371][372][373] No further structural changes are found in this material. Despite the strong softening of the polar mode near -273 °C, zero-point motion suppresses ferroelectricity.…”

Thermoelectric and structural correlations in (Sr1−x−yCaxNSomaily1, Koleśnik2, Dąbrowski3 et al. 2017Phys. Rev. B5040View full textAdd to dashboardCite

“…6. The unit cell volume of the parent SrTiO 3 [13,[61][62][63] and CaTiO 3 [28,54,64] materials are shown for comparison.…”

“…Phase transition temperatures Ts both measured (from our NPD structural refinement results in the temperature range 13-300K) and calculated (by extrapolating and fitting the t factor above room temperature to a power law in T in the form t(T) = t 0(T=0) +AT n , with n=2 as shown in Fig. 8 and 9) are summarized in Table 4 and compared to the values acquired from synchrotron x-ray data and to the available literature data [13,28,61,68].…”