The Polar Nano Regions $\rightleftharpoons$ Relaxor Transition in $Pb_{1-X}(Sc_{1/2}Nb_{1/2})O_{3-X}$; $X$ = bulk concentration of nearest neighbor [Pb-O] divacancies

TL;DR

This study uses molecular dynamics simulations to explore phase diagrams of PSN, revealing additional relaxor phases and supporting the analogy between relaxors and spin-glass systems.

Contribution

It introduces new relaxor regions in the phase diagrams of PSN, enhancing understanding of relaxor behavior and its similarity to spin-glass systems.

Findings

Additional relaxor phases predicted in phase diagrams.

Strong support for analogy between relaxors and spin-glass systems.

Phase diagrams include regions with glassy relaxor states.

Abstract

In previous work, molecular dynamics simulations based on a first-principles-derived effective Hamiltonian for $Pb_{1-X}(Sc_{1/2}Nb_{1/2})O_{3-X}$~ (PSN), with nearest-neighbor Pb-O divacancy pairs, was used to calculate $X_{\rm [Pb-O]}$~vs.~T, phase diagrams for PSN with: ideal rock-salt type chemical order; nanoscale chemical short-range order; and random chemical disorder. Here, we show that the phase diagrams should include additional regions in which a glassy relaxor-phase (or state) is predicted. With respect to phase diagram topology, these results strongly support the analogy between relaxors and magnetic spin-glass-systems.