Please use this identifier to cite or link to this item:
|Title:||Role of intrinsic disorder in the structural phase transition of magnetoelectric EuTiO3||Authors:||Allieta, Mattia
Spalek, Leszek J.
Walker, Helen C.
Saxena, Siddharth S.
|Keywords:||DRNTU::Science::Chemistry::Crystallography||Issue Date:||2012||Source:||Allieta, M., Scavini, M., Spalek, L. J., Scagnoli, V., Walker, H. C., Panagopoulos, C., et al. (2012). Role of intrinsic disorder in the structural phase transition of magnetoelectric EuTiO3. Physical Review B, 85(18), 184107-.||Series/Report no.:||Physical review B||Abstract:||Up to now, the crystallographic structure of the magnetoelectric perovskite EuTiO3 has been considered to remain cubic down to low temperature. Here we present high-resolution synchrotron x-ray powder-diffraction data showing the existence of a structural phase transition, from cubic Pm-3m to tetragonal I4/mcm, involving TiO6 octahedra tilting, in analogy to the case of SrTiO3. The temperature evolution of the tilting angle and of the full width at half maximum of the (200) cubic reflection family indicate a critical temperature Tc = 235 K. This critical temperature is well below the recent anomaly reported by specific-heat measurement at TA ∼ 282 K. By performing atomic pair distribution function analysis on diffraction data, we provide evidence of a mismatch between the local (short-range) and the average crystallographic structures in this material. Below the estimated Tc, the average model symmetry is fully compatible with the local environment distortion, but the former is characterized by a reduced value of the tilting angle compared to the latter. At T = 240 K, data show the presence of local octahedra tilting identical to the low-temperature one, while the average crystallographic structure remains cubic. On this basis, we propose that intrinsic lattice disorder is of fundamental importance in the understanding of EuTiO3 properties.||URI:||https://hdl.handle.net/10356/95003
|DOI:||10.1103/PhysRevB.85.184107||Rights:||© 2012 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The paper can be found at the following official DOI: [http://dx.doi.org/10.1103/PhysRevB.85.184107]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.||Fulltext Permission:||open||Fulltext Availability:||With Fulltext|
|Appears in Collections:||SPMS Journal Articles|
Files in This Item:
|17. Role of intrinsic disorder in the structural.pdf||1.79 MB||Adobe PDF|
Updated on Feb 26, 2021
Updated on Mar 1, 2021
Page view(s) 10535
Updated on Mar 4, 2021
Updated on Mar 4, 2021
Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.