Tunable optical and magnetic properties of Tm-doped AlN nanostructures

•AlN:Tm nanostructures were synthesized by direct nitridation method.•AlN:Tm nanostructures exhibited room temperature ferromagnetism.•The optical and magnetic properties of AlN:Tm can be regulated by tuning the architectures. Tm doped AlN (AlN:Tm) nanostructures such as nanowalls and hexagonal nanopillars were synthesized by plasma-assisted direct nitridation method without any catalyst or template. The AlN:Tm nanowalls exhibit strong photoluminescence in blue (460–480 nm), while nanopillars show strong emission lines in the near infrared spectral region (790–820 nm). Through hysteresis measurements, both AlN:Tm nanostructures exhibit room-temperature ferromagnetism. The saturation magnetization of AlN:Tm nanopillars is obviously larger than that of the nanowalls due to the geometry morphology. Both optical and magnetic properties of AlN:Tm nanostructures can be regulated through tuning the architectures. This work provides a new opportunity to design promising materials for optoelectronic and magnetic functionalities on a single chip.