Functional ABC intermetallics from first principles

Ternary ABC intermetallic compounds exhibit a rich variety of crystal structures and electronic properties. In this work, we study the structural energetics and band structures of real and hypothetical ABC intermetallic phases, primarily hexagonal and half-Heusler phases. We use first principles calculations to determine the structural parameters and the bands in each phase and the effects of strain and strain gradients on the properties and relative energies of competing phases. We connect these results to experimental measurements on known hexagonal ABC phases. The possibility of strain control and switchability of the polar distortion in polar metallic phases by strain gradients offers the promise of functional magnetic, optical, and transport properties, with examples to be discussed.