Simulation of PNR-PNR Correlations in Pb(Sc1/2Nb1/2)O3; Support/Implications for the Spherical Random Bond Random Field Model

Published

February 19, 2017

Author(s)

Benjamin P. Burton, Eric J. Cockayne, U Waghmare

Abstract

First principles based molecular dynamics simulations were performed on a 40^3^ unit cell system of stoichiometry Pb(Sc_1/2Nb_1/2)O₃ (PSN). To imitate a realistic relaxor ferroelectric texture, the chemical microstructure was subdivided into 80 regions of 800 unit cells each, of which: 20 were chemically ordered regions (COR); and 60 were chemically disordered regions (CDR). The system exhibits a ferroelectric transition at TFE 600K. Time averaged magnitudes of cluster polarizatons, ||, are larger for COR than CDR at all temperatures, and the magnitudes of cluster-cluster correlations follow the trend: COR-COR correlations stronger than COR-CDR correlations stronger than CDR-CDR correlations. Within the length scale sampled by these simulations, cluster-cluster correlations exhibit no dependence on iner-cluster separation. These results are interpreted as indicating that polar nano-regions (PNR), nucleate on COR, and interact in a way that is strongly suggestive of the spherical random bond random field model.

Citation

Physical Review Letters

Pub Type

Journals

Keywords

Pb(Sc_1/2Nb_1/2)O₃, phase transitions, polar nano regions, PSN, random field model, relaxor ferroelectrics, spherical random bond

Citation

Burton, B. , Cockayne, E. and Waghmare, U. (2017), Simulation of PNR-PNR Correlations in Pb(Sc_1/2Nb_1/2)O₃; Support/Implications for the Spherical Random Bond Random Field Model, Physical Review Letters (Accessed July 18, 2024)