Abstract
During the last decade the cubic perovskite oxide EuTiO3 (ETO) has attracted enormous novel research activities due to possible multiferroicity, hidden magnetism far above its Néel temperature at TN = 5.5 K, structural instability at TS = 282 K, possible application as magneto-electric optic device, and strong spin–lattice coupling. Here we address a novel highlight of this compound by showing that well below TS a further structural phase transition occurs below 210 K without the application of an external magnetic field, and by questioning the assumed tetragonal symmetry of the structure below TS where tiny deviations from true tetragonality are observed by birefringence and XRD measurements. It is suggested that the competition in the second nearest neighbor spin–spin interaction modulated by the lattice dynamics is at the origin of these new observations.
Highlights
DiscussionOne might argue that the observed length differences (Fig. 5) are too tiny to influence any possible magnetic or structural responses, in various earlier work it has been shown that changes in the lattice constant, the Eu–O bond distance, respectively, of less than 0.01%, i.e. of the order of 1 0–4 Å, can cause, e.g., a ferroelectric phase transition or a transition from AFM to PM
We address a novel highlight of this compound by showing that well below TS a further structural phase transition occurs below 210 K without the application of an external magnetic field, and by questioning the assumed tetragonal symmetry of the structure below TS where tiny deviations from true tetragonality are observed by birefringence and XRD measurements
We have reported that bulk ETO and films of ETO are susceptible to an external magnetic field of relatively low intensity
Summary
One might argue that the observed length differences (Fig. 5) are too tiny to influence any possible magnetic or structural responses, in various earlier work it has been shown that changes in the lattice constant, the Eu–O bond distance, respectively, of less than 0.01%, i.e. of the order of 1 0–4 Å, can cause, e.g., a ferroelectric phase transition or a transition from AFM to PM. Pair distribution function (PDF)[27,28,29] data support these results. It implies that ETO is on the verge of various structural instabilities under pressure or strain[30] where in[30] support for deviations from tetragonality have been observed at low pressure.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
