Abstract
While the unique geometrical frustration of pyrochlore Yb2Ti2O7 has attracted attention, the dielectric and other properties of this pyrochlore beyond frustrated magnetism are not well understood. Here, we report on the fascinating low-temperature dielectric relaxation of Yb2-xBaxTi2O7-δ (x = 0–0.20) and demonstrate that this phenomenon is related to structural distortion. A-site Ba substitution, which increases the density of point defects and introduces a different atomic radius, enhances the chemical disorder and structural distortion. As a result, the increases in oxygen vacancies and nonmagnetic Ba2+ and Yb2+ ions dilute the ferromagnetic Yb3+–Yb3+ interactions, as indicated by the decrease in effective magnetic moment. On the other hand, the distorted octahedra facilitate the hopping of Yb ions, and the random distribution of Ba2+ ions at the Yb3+ sites gives rise to additional random fields, leading to significantly increased dielectric relaxation. The room-temperature dielectric constant is improved to ∼170, twice that of pristine Yb2Ti2O7. This work provides a comprehensive view of the structural, magnetic, and dielectric properties of Yb2Ti2O7 and lays the foundation for additional research into pyrochlore compounds.
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.
