Compositional nanodomain formation in hybrid formate perovskites

TL;DR

This study synthesizes and characterizes mixed-metal formate perovskites, revealing compositional nanodomains in Mn and Zn variants and a miscibility gap in Mg, advancing understanding of nanodomain formation in hybrid perovskites.

Contribution

It introduces new mixed-metal formate perovskite families and demonstrates nanodomain formation using advanced spectroscopic and computational techniques.

Findings

Mn and Zn compounds support compositional nanodomains

Mg family shows a miscibility gap

Nanodomains resemble relaxor ferroelectric regions

Abstract

We report the synthesis and structural characterisation of three mixed-metal formate perovskite families [C(NH$_2$)$_3$]M$_{1-x}$Cu$_x$(HCOO)$_3$ (M = Mn, Zn, Mg). Using a combination of infrared spectroscopy, non-negative matrix factorization, and reverse Monte Carlo refinement, we show that the Mn- and Zn-containing compounds support compositional nanodomains resembling the polar nanoregions of conventional relaxor ferroelectrics. The M = Mg family exhibits a miscibility gap that we suggest reflects the limiting behaviour of nanodomain formation.