Recently, Associate Professor Dawei Wang published his newest research result in Nature Communications (IF: 11.470). The title is "Subterahertz dielectric relaxation in lead-free Ba(Zr,Ti)O3 relaxor ferroelectrics".
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.
D.W. acknowledge the support of the Air Force Office of Scientific Research under Grant FA9550-16-1-0065 and ONR Grant N00014-12-1-1034, also acknowledge the support from National Natural Science Foundation of China (Grant Nos. 51390472 and 11574246).
Link:http://www.nature.com/ncomms/2016/160404/ncomms11014/full/ncomms11014.html
