Spatially confined alloy single crystals for model studies of volumetrically constrained phase transformations

摘要

The authors present a method to fabricate confined, oriented, single crystals of ternary alloys within an inert ceramic matrix. Pulsed-laser deposition of a polycrystalline CuNiFe film fills lithographically defined surface cavities in a sapphire single crystal. Solid-state diffusion bonding to a second sapphire crystal internalizes the metal-filled cavities. Electron microscopy verifies that subsequent heat treatment converts the thin, fully constrained films into single crystals of specific orientation by nucleation-controlled liquid-phase epitaxy during cooling from above the alloy melting temperature. The resulting films provide an ideal medium for fundamental studies of a wide range of volumetrically constrained phase transformations.