Effect of samarium doping on structural, optical and magnetic properties of vertically aligned ZnO nanorod arrays

Samarium doped vertically aligned one dimensional ZnO nanorod (NR) arrays were grown by vapor phase transport (VPT) method through vapor solid (VS) growth process. Influence of different concentrations (0% to 8%) of Sm (all Sm contents in the paper are in mass fraction) on the ZnO NR arrays were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL), Raman spectroscopy and vibrating sample magnetometry (VSM) techniques, respectively. X-ray diffraction studies revealed that the ZnO NR arrays were perfectly oriented along (002) crystallographic orientation with wurtzite crystal structure. Photoluminescence results showed an increase in oxygen vacancies due to increase in Sm doping. M-H curves revealed enhanced ferromagnetic behavior, and the magnetic moment values were 0.45, 0.363, 1.694, 3.613 and 2.197 emu/cm(3) for (0-8%) Sm doped ZnO NR arrays respectively. The curve revealed that paramagnetic behavior was observed for undoped ZnO NR arrays and on increasing the Sm dopant to 4%, paramagnetic switched to ferromagnetic behavior.