Role of surface functionalization in ZnO:Fe nanostructures

In this work, we have explored the effect of surface functionalization in ZnO:Fe nanostructures. The ZnO:Fe nanostructures (NS), synthesized through hydrothermal route, have been surface functionalized (capped) by Tri-n-butylamine (amine). These samples have been characterized by X-ray diffraction (XRD), photoluminescence (PL) and Fourier transform infrared spectroscopy (FTIR). Field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM) illustrate that obtained nanostructures are high aspect ratio nanorods. Room temperature Mِssbauer spectra (MS) of the samples indicate the presence of paramagnetic iron state i.e. Fe3+ in ZnO host. The ferromagnetic (FM) behavior of the samples was investigated by vibrating sample magnetometer (VSM) which shows that the significant enhancement of saturation magnetization in amine capped ZnO:Fe samples. This observed/enhanced ferromagnetism has been explained in terms of modification in the ZnO conduction band. The enhanced ferromagnetism due to surface functionalization has been justified by XRD, PL, FTIR and MS.