Single crystal growth and characterization of Ba$_2$ScNbO$_6$ -- a novel substrate for BaSnO$_3$ films

TL;DR

This study reports the first successful growth and detailed characterization of large single crystals of Ba$_2$ScNbO$_6$, a promising new substrate material with excellent lattice match for BaSnO$_3$ films and other perovskites.

Contribution

The paper introduces a novel method for growing large single crystals of Ba$_2$ScNbO$_6$ and provides comprehensive characterization data.

Findings

Ba$_2$ScNbO$_6$ melts at 2165±30°C in inert atmosphere.

Crystals exhibit high-quality (100)-oriented surfaces with low mosaic spread.

Large single-crystal substrates suitable for epitaxial film growth were produced.

Abstract

Large single crystals of the double-perovskite Ba$_2$ScNbO$_6$ were grown from the melt for the first time. With a lattice parameter at room temperature of 4.11672(1) \r{A}, this cubic double-perovskite has an excellent lattice match to BaSnO$_3$, PbZr$_{0.9}$Ti$_{0.1}$O$_3$, LaInO$_3$, BiScO$_3$, and other perovskites of contemporary interest. Differential thermal analysis showed that Ba$_2$ScNbO$_6$ melts at 2165$\pm$30{\deg}C in an inert atmosphere. Competitive grain growth was visualized by energy dispersive Laue mapping. X-ray diffraction rocking curve measurements revealed full width at half maximum values between 21 and 33 arcsec for 002 and 004 reflections. The crystals were sufficiently large to yield (100)-oriented single-crystal substrates with surface areas as large as 10 x 10 mm$^2$.