RAPID AND COST EFFECTIVE SYNTHESIS OF ZnO NANORODS USING MICROWAVE IRRADIATION TECHNIQUE

Abstract

ZnO nanorods assembled in flower shaped morphology have been successfully synthesized using low power microwave irradiation in a very short duration. The diameter and length of the rods were within 150–190 nm (tip diameter ~15 nm) and 2 μm, respectively, with an aspect ratio of 20–22. The synthesized nanorods were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared microscopy (FT-IR), photoluminescence (PL) and magnetization measurements. The XRD and FT-IR results indicate that ZnO nanorods have the pure wurtzite structure with lattice parameters a and c of 3.254 and 5.197 Å, respectively. The selected area electron diffraction (SAED) pattern reveals that the ZnO nanorods are single crystal in nature and grow along [001] plane. Room-temperature PL spectrum of the as-grown ZnO nanorods shows a near-band-edge (NBE) emission peak and defect induced emissions. Magnetization measurements indicate that ZnO nanorods exhibit room temperature ferromagnetism with remanent magnetization (M r ) and coercivity (H c ) about 2.92 × 10-4 (emu/g) and 29.75 Oe , respectively, which may be due to the presence of defects in the ZnO nanorods.