title: Subterahertz dielectric relaxation in lead-free Ba(Zr,Ti)O3 relaxor ferroelectrics.
abstract: Relaxors are complex materials with unusual properties that have been puzzling the scientific community since their discovery. The main characteristic of relaxors, that is, their dielectric relaxation, remains unclear and is still under debate. The difficulty to conduct measurements at frequencies ranging from ≃1 GHz to ≃1 THz and the challenge of developing models to capture their complex dynamical responses are among the reasons for such a situation. Here, we report first-principles-based molecular dynamic simulations of lead-free Ba(Zr0.5Ti0.5)O3, which allows us to obtain its subterahertz dynamics. This approach reproduces the striking characteristics of relaxors including the dielectric relaxation, the constant-loss behaviour, the diffuse maximum in the temperature dependence of susceptibility, the substantial widening of dielectric spectrum on cooling and the resulting Vogel-Fulcher law. The simulations further relate such features to the decomposed dielectric responses, each associated with its own polarization mechanism, therefore, enhancing the current understanding of relaxor behaviour.
authors.affiliation: Electronic Materials Research Laboratory-Key Laboratory of the Ministry of Education and International Center for Dielectric Research, School of Electronic and Information Engineering, Xi'an Jiaotong University, No. 28, Xianning West Road, Xi'an 710049, China.
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Chemistry and 4D LABS, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1A6.
authors.forename: A A
authors.initials: AA
authors.lastname: Bokov
authors.affiliation: Electronic Materials Research Laboratory-Key Laboratory of the Ministry of Education and International Center for Dielectric Research, School of Electronic and Information Engineering, Xi'an Jiaotong University, No. 28, Xianning West Road, Xi'an 710049, China.|Department of Chemistry and 4D LABS, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1A6.
authors.forename: Z-G
authors.initials: ZG
authors.lastname: Ye
authors.affiliation: Department of Dielectrics, The Czech Academy of Sciences, Na Slovance 2, CZ-182 21 Praha 8, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Hlinka
authors.affiliation: Department of Physics and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors.forename: L
authors.initials: L
authors.lastname: Bellaiche