Work

Effects of digital doping with Mn in the structural and ferromagnetic properties of AlN

Year: 2026

Type: article

Abstract: We have investigated the growth of AlN doped with Mn by molecular beam epitaxy (MBE) using an alternating flux supply method, where Al and Mn fluxes are modulated while maintaining a constant nitrogen flux (digital doping growth). Vibrating sample magnetometry showed that Mn digital doping induced room-temperature ferromagnetism in AlN, with enhanced magnetic moments compared with samples grown by conventional MBE. Raman spectroscopy revealed a more pronounced local vibrational mode associated with Mn at Al sites in samples grown by digital doping, indicating a more effective Mn incorporation in cation sites. The digital growth conditions at low-temperature favored AlN nanodots formation on the surface, not observed in samples grown by conventional MBE. Nanodot formation on the surface was evidenced by chevron patterns in reflection high-energy electron diffraction (RHEED) and confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Atomic force microscopy (AFM) revealed nanodots with an average height of 4.2 nm and width of 50.3 nm. Magnetic force microscopy (MFM) showed that nanodot formation influences magnetic domain behavior, enhancing ferromagnetic interactions under applied fields. These findings emphasize the role of Mn digital doping with nanodot formation in enhancing ferromagnetism in AlN:Mn.

Source: Applied Surface Science

DOI: 10.1016/j.apsusc.2026.166418