Synthesis and Properties of SmN Thin Films grown on MgO(001)

We demonstrate the growth of high-quality SmN thin films on MgO(001) using molecular beam epitaxy. Furthermore, the SmN electronic properties can be effectively tuned during growth by controlling the synthesis parameters, driving the film from an insulating ferromagnetic state to a ferromagnetic metallic state. We do not observe signatures of superconductivity in any of the samples synthesized, even down to 0.35 K. We discuss possible scenarios for the absence of superconductivity in these films and examine implications for the underlying pairing mechanism in this material. Our results provide a pathway for high-quality synthesis of SmN thin films and its potential monolithic integration in spintronic devices based on rare-earth nitride systems.