Simulation of PNR-PNR Correlations in Pb(Sc1/2Nb1/2)O3; Support/Implications for the Spherical Random Bond Random Field Model
Benjamin P. Burton, Eric J. Cockayne, U Waghmare
First principles based molecular dynamics simulations were performed on a 40^3^ unit cell system of stoichiometry Pb(Sc1/2Nb1/2)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.
Physical Review Letters
Pb(Sc<sub>1/2</sub>Nb<sub>1/2</sub>)O<sub>3</sub>, phase transitions, polar nano regions, PSN, random field model, relaxor ferroelectrics, spherical random bond
, Cockayne, E.
and Waghmare, U.
Simulation of PNR-PNR Correlations in Pb(Sc<sub>1/2</sub>Nb<sub>1/2</sub>)O<sub>3</sub>; Support/Implications for the Spherical Random Bond Random Field Model, Physical Review Letters
(Accessed October 4, 2023)