Tuning of electronic properties in highly lattice-mismatched epitaxial SmN

TL;DR

This study shows how to tune the electronic and magnetic properties of epitaxial SmN thin films through growth parameters, achieving transitions from insulating to metallic states, but without observing superconductivity.

Contribution

It demonstrates a method to control electronic phases in SmN films during growth, enabling integration of ferromagnetism and metallicity without lattice mismatch issues.

Findings

Tunable transition from insulating to metallic ferromagnetic states.

No superconductivity observed down to 0.35 K.

Potential for epitaxial engineering of multifunctional materials.

Abstract

We demonstrate that the electronic properties of epitaxial SmN thin films can be effectively tuned during growth by controlling the synthesis parameters. By carefully adjusting these parameters, we are able to drive SmN from an insulating ferromagnetic state to a ferromagnetic metallic state. However, no signatures of previously reported superconductivity were observed down to 0.35 K, even in the most conductive samples. We discuss possible scenarios for the absence of superconductivity in these films and examine implications for the underlying pairing mechanism in this material. These findings open a new pathway for the epitaxial engineering of multifunctional materials, enabling the monolithic integration of diverse electronic phases, such as ferromagnetism and metallicity, without the lattice mismatch and strain typically associated with heteroepitaxial growth of dissimilar materials.