Development of a Geometric Descriptor for the Strategic Synthesis of Remeika Phases

Remeika
phases, also described as pseudoperovskites, are cage-like
structures with emergent properties. In this Perspective, we first
cover heuristic methods used to overcome the challenges to rationalize
the stability of extended solids. We highlight the important role
Goldschmidt’s tolerance factor has played in enhancing research
related to perovskites and their derivatives. We discuss the development
of a tolerance factor for predicting the stability of intermetallic
pseudoperovskites, the Remeika phases, and rationalize oxidation states
in correlation with valence fluctuation. To evaluate the feasibility
of the Remeika phase tolerance factor, we synthesized the new predicted
compound Yb5Ru6Sn18 with a magnetic
moment (μeff) of 3.2 μB/Yb. We then
highlight the importance of determining the factors dictating the
stability of the Remeika intermetallics.