# Crystal growth and structural analysis of perovskite chalcogenide BaZrS$_3$ and Ruddlesden-Popper phase Ba$_3$Zr$_2$S$_7$

## TL;DR

This study successfully grew high-quality BaZrS$_3$ and Ba$_3$Zr$_2$S$_7$ crystals, analyzing their structures and confirming their suitability for optoelectronic applications through advanced characterization techniques.

## Contribution

First demonstration of high-quality crystal growth and detailed structural analysis of BaZrS$_3$ and its Ruddlesden-Popper phase Ba$_3$Zr$_2$S$_7$ using flux method.

## Key findings

- Crystals exhibit high structural quality with narrow rocking curves.
- X-ray diffraction confirms space groups and lattice parameters.
- Structural analysis reveals octahedral tilting and torsion angles.

## Abstract

Perovskite chalcogenides are gaining substantial interest as an emerging class of semiconductors for optoelectronic applications. High quality samples are of vital importance to examine their inherent physical properties. We report the successful crystal growth of the model system, BaZrS$_3$ and its Ruddlesden-Popper phase Ba$_3$Zr$_2$S$_7$ by flux method. X-ray diffraction analyses showed space group of $Pnma$ with lattice constants of $a$ = 7.056(3) \AA\/, $b$ = 9.962(4) \AA\/, $c$ = 6.996(3) \AA\/ for BaZrS$_3$ and $P4_2/mnm$ with $a$ = 7.071(2) \AA\/, $b$ = 7.071(2) \AA\/, $c$ = 25.418(5) \AA\/ for Ba$_3$Zr$_2$S$_7$. Rocking curves with full-width-at-half-maximum of 0.011$^\circ$ for BaZrS$_3$ and 0.027$^\circ$ for Ba$_3$Zr$_2$S$_7$ were observed. Pole figure analysis, scanning transmission electron microscopy images and electron diffraction patterns also establish high quality of grown crystals. The octahedra tilting in the corner-sharing octahedra network are analyzed by extracting the torsion angles.