Magnetic and Electronic Properties of Fe_(0.1)Sc_(0.9)N/ScN(001)/MgO(001) Grown by Radio-Frequency Molecular Beam Epitaxy

摘要

Fe_(0.1)Sc_(0.9)N with a thickness of ～ 380 nm was grown on top of a ScN(001) buffer layer of ～ 50 nm, grown on MgO(001) substrate by radio-frequency N-plasma molecular beam epitaxy (rf-MBE). The buffer layer was grown at Ts ～800°C, whereas the Fe_(0.1)Sc_(0.9)N(001) film was grown at Ts ～420°C. In-situ reflection high-energy electron diffraction measurements show that the Fe_(0.1)Sc_(0.9)N film growth starts with a combination of spotty and streaky pattern [indicative of a combination of smooth and rough surface]. After ～ 10 minutes of growth, the pattern converts to a spotty one [indicative of a rough surface]. Towards the end of the Fe_(0.1)Sc_(0.9)N film growth, the spotty pattern transforms into even spottier, but also ring-like indicating a polycrystalline behavior. Superconducting quantum interference device magnetic measurements show a ferromagnetic to paramagnetic transition of T_C ～ 370 - 380 K. We calculated a magnetic moment per atom of μ_(0.1 0.9)~(Fe Sc N) = 0.037 Bohr magneton/Fe-atom. Based on the carrier concentration measurements (n_(S 0.1 0.9)~(Fe Sc N) = 2.086 × 10~(19)/cm~3), we find that iron behaves as an acceptor. Comparisons are made with similar MnScN (001)/ScN(001)/MgO(001) system.