High Quality Growth of Cobalt Doped GaN Nanowires with Enhanced Ferromagnetic and Optical Response

Abstract

Group III–V semiconductors with direct band gaps have become crucial for optoelectronic and microelectronic applications. Exploring these materials for spintronic applications is an important direction for many research groups. In this study, pure and cobalt doped GaN nanowires were grown on the Si substrate by the chemical vapor deposition (CVD) method. Sophisticated characterization techniques such as X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Transmission Electron Microscopy (TEM), High-Resolution Transmission Electron Microscopy (HRTEM) and photoluminescence (PL) were used to characterize the structure, morphology, composition and optical properties of the nanowires. The doped nanowires have diameters ranging from 60–200 nm and lengths were found to be in microns. By optimizing the synthesis process, pure, smooth, single crystalline and highly dense nanowires have been grown on the Si substrate which possess better magnetic and optical properties. No any secondary phases were observed even with 8% cobalt doping. The magnetic properties of cobalt doped GaN showed a ferromagnetic response at room temperature. The value of saturation magnetization is found to be increased with increasing doping concentration and magnetic saturation was found to be 792.4 µemu for 8% cobalt doping. It was also depicted that the Co atoms are substituted at Ga sites in the GaN lattice. Furthermore N vacancies are also observed in the Co-doped GaN nanowires which was confirmed by the PL graph exhibiting nitrogen vacancy defects and strain related peaks at 455 nm (blue emission). PL and magnetic properties show their potential applications in spintronics.

Magnetic properties of Mn-doped InSb nanowires from first principles

“…Since an experimental reports of T C reaching 200K in (Ga,Mn)As by patterning a heavily Mn-doped (Ga,Mn)As films into NWs [23], this success has inspired researchers to be interested in DMS NWs that takes advantage of the quantum size effect and surface effect of the NW. At the experimental level, the room temperature DMS NWs were developed using Mn-doped GaN NWs [24], Co-doped GaN NWs [25,26], Co-doped ZnO NWs [27], and (Cu,N)-codoped In 2 O 3 NWs [28]. Theoretically, Zhang et al suggested that the magnetic moment and the ferromagnetic states in (Ga,Mn)As NWs can be effectively regulated by the surface dangling bonds [29].…”

One-Dimensional Mn5Si3 Nanorods: Fabrication, Microstructure, and Magnetic Properties via a Novel Casting-Extraction Route

“…are a research focus in the scientific community due to their unique structures and integration of unusual physical properties. With unique advantages in the fields of electrics, optics, and magnetism, 1D nanomaterials hold immense promise in relevant nanotechnology applications [1][2][3][4][5][6][7][8][9][10]. Recently, nanostructured manganese silicides, including MnSi, Mn 5 Si 3 , Mn 3 Si, etc., received significant attention for their potential use in magnetic and spintronic applications [11][12][13][14][15][16].…”