Study on Ferromagnetism in Mn-implanted GaN Nanorods Followed by Thermal Annealing

Abstract

One-dimensional ferromagnetic semiconductor nanostructures such as Mn-doped GaN nanorods, suitable for controlled fabrication and magnetic doping, are cutting-edge in the development of spin-based multifunctional devices as well as for the understanding of fundamental properties. we herein aim at the fabrication of high-purity in situ Mn-doped single-crystal GaN nanorods via a by radio-frequency plasma-assisted molecular-beam epitaxy method without catalyst, template mediation, or co-doping. The high purity of the samples was ensured, since they were produced in bulk quantity by a simple, one-step and in situ doping process without any metal catalyst. We looked at the magnetic and optical characteristics of dislocation-free vertical GaN nanorods with diameters of 150 nm that were formed on (111) Si substrates using radio-frequency plasma-assisted molecular-beam epitaxy, then Mn ion implantation, and then annealing. The GaN nanorods have excellent crystal quality, are totally relaxed, and exhibit highly strong and confined photoluminescence excitonic lines about 3.47 eV. For GaMnN nanorods, it can be indicated that the ferromagnetic property of GaMnN nanorods with a Curie temperature greater than 300 K is affiliated with the formation of Mn4Si7 magnetic phase, which ultimately resulted from the effects of magnetic and structural disorder introduced by a random incorporation and inhomogeneous distribution of Mn atoms in the porous layer between the nanorods that form precipitates in the Si substrate before or during the annealing step amongst the GaN nanorods.