Synthesis and characterization of pure and Co-doped gallium nitride nanocrystals

Abstract

Pure and Co-doped gallium nitride (GaN) (5 and 8 mol%) nanocrystals were synthesized by nitridation of Ga-EDTA.NH 4 and Co-Ga-EDTA.NH 4 complexes. Pure and 5 mol% cobalt-doped GaN did not show any impurity phases in the X-ray diffraction and Raman analysis, whereas 8 mol% Co-doped GaN show secondary phase formation. Transmission electron microscopic study revealed the broad crystal size distribution ranging from 10 to 140 nm. Cathodoluminiscence spectra measured at 20 K shows the suppression of GaN band edge emission with increasing Co concentration. Magnetic measurements of Co-doped GaN revealed a ferromagnetic behavior up to room temperature. The saturation magnetization value increases with increasing impurity phase separation. X-ray photoelectron spectroscopy revealed evidence on the oxidation states of cobalt and excludes the possibility of Co clusters in the doped samples.

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

“…Miller indices of the hexagonal GNNWs are also marked in the graphs relevant to the peaks. It is noted that the doping of cobalt in GaN resulted in the shifting of peaks to the smaller angles which caused an increase in lattice parameters, as reported in the literature [24]. Furthermore, the doping with cobalt did not modify the diffraction profile of GaN.…”

“…Gallium nitride with a direct band gap (3.4 eV) is one of the ideal materials for ultraviolet (UV) and blue emitters, high-speed FETs and high-power electronic devices, which makes it a suitable candidate to develop spintronic devices. There are different reports on the doping of GaN with other TM and rare-earth elements, such as Mn [ 9 , 10 , 11 ], Cr [ 12 , 13 , 14 ], Gd [ 15 , 16 ], Dy [ 14 ], Eu [ 17 ], Co [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ], V [ 25 ] and Fe [ 26 , 27 , 28 , 29 , 30 , 31 ]. These studies were mainly focused on bulk semiconductors, but the demand of next generation electronic devices with a minimum size but the same extraordinary properties as bulk material is increasing in the society.…”

Electrodeposition of gallium in the presence of NH4Cl in an ionic liquid: hints for GaN formation

“…This might be due to either strain within the GaN or due to doping in the GaN. 24,25 As in the case of the electrodeposited GaN, the formation of CuGa 2 alloy took place, therefore there are possibilities that both strain and doping has affected the GaN electrodeposit.…”