Ordering and phonons in Ba$_3$CaNb$_{2}$O$_9$ complex perovskite

TL;DR

This study investigates how sintering conditions affect the atomic ordering and phonon properties in Ba$_3$CaNb$_{2}$O$_9$ perovskite using Raman spectroscopy and ab initio calculations.

Contribution

It introduces a combined experimental and theoretical approach to analyze ordering in complex perovskites, highlighting the impact of sintering temperature and time.

Findings

Higher sintering temperature enhances atomic order.

Sintering time has limited effect on order.

Ab initio calculations successfully assign optical phonons.

Abstract

In this work we performed a detailed investigation about ordering in \bcn perovskite. The sintering temperature and time were changed to obtain samples with different ordering. The order parameters were probed by Raman spectroscopy based on a partial disordered model. To use the partial disordered model correctly we performed {\it ab initio} calculations in \bcn to assign the optical phonons. The results showed that sintering temperature improves order while sintering time is not so efficient to promote order.