Synthesis and Magnetic Characterization of Bismuth Doped ZnO Nanowires

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. However due to oxidation the ferromagnetism induced by defects is unstable. In the present work the solution process synthesis route was utilized to grow pristine and bismuth-doped highly crystalline ZnO nanowire (ZnO NW)-based samples. The magnetization (M-H) curve of all samples shown ferromagnetic behavior at room temperature. The saturation magnetization for Bi-doped ones is ±0.25 emu/g and for undoped it is ±2.0 emu/g so almost a 10 times larger magnetization. Laser Induced Breakdown Spectroscopy (LIBS) spectra confirmed the presence of dopant elements in the ZnO. X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) shown pronounced 002 peak along c-axis having hexagonal top face respectively. The XRD peak broadening was used to estimates stress and it came out to be 2.51x10-2 for pristine ZnO & 5.80x10-2 for Bi-doped ZnO NWs. UV-Vis shown the change in the bandgap of ZnO NWs after doping.