Mapping Chemical Disorder and Ferroelectric Distortions in the Double Perovskite Compound Sr2-xGdxMnTiO6 by Atomic Resolution Electron Microscopy and Spectroscopy. (1st April 2014)

• Record Type: Journal Article
• Authors: Biškup, Neven; Álvarez-Serrano, Inmaculada; Veiga, Maria; Rivera-Calzada, Alberto; Garcia-Hernandez, Mar; Pennycook, Stephen J.; Varela, Maria
• Is Part Of: Microscopy and microanalysis. Volume 20(2014)Supplement 3
• Page Start: 731
• Page End: 739
• Publication Date: 2014-04-01
• Subjects: double perovskite, -- electroresistance, -- ferroelectric displacement, -- atomic resolution electron microscopy, -- EELS; Microscopy -- Periodicals; Microchemistry -- Periodicals; 502.82
• DOI: 10.1017/S1431927614000506
• Languages: English
• ISSNs: 1431-9276

Abstract

Abstract: In this work we report a study of the chemical and structural order of the double perovskite compound Sr2- x Gd x MnTiO6 for compositions x =0, 0.25, 0.5, 0.75, and 1. A noticeable disorder at the B-site in the Mn and Ti sublattice is detected at the atomic scale by electron energy-loss spectroscopy for all x values, resulting in Mn-rich and Ti-rich regions. For x ≥0.75, the cubic unit cell doubles and lowers its symmetry because of structural rearrangements associated with a giant ferroelectric displacement of the perovskite B-site cation. We discuss this finding in the light of the large electroresistance observed in Sr2- x Gd x MnTiO6, x ≥0.75.