Effect of Mn-substitution on impedance spectroscopy and magnetic properties of Al-doped ZnO nanoparticles.

In this study, the role of Mn-substitution on structural, morphological, dielectric and magnetic properties of Al-doped ZnO nanoparticles has been examined using XRD, FE-SEM, muAutolab/FRA2 impedance spectroscopy, and vibrating sample magnetometer (VSM) techniques. The structural investigations have revealed that diffraction peaks consistent with the JCPDS card No. 036-1451. The Morphological evaluations of the synthesized nanoparticles indicated that the shape of the nanoparticles is a slightly hexagonal and chiefly spherical structure with size ranges of about 10-70 nm. The dielectric measurements have been performed in the frequency ranges between 10-3 Hz to 1 MHz. The results show that samples dielectric behavior is affected by the crystallite size and doping material type. Also, it reveals that the dielectric parameters exhibit extreme frequency dependence. Mn-substituted Al-doped ZnO sample is a suitable candidate for high-frequency applications due to its low dielectric loss at high frequencies. AC conductivity of the Mn-substituted Al-doped ZnO sample increases with frequency increment and its value is higher than the Al-doped ZnO sample which makes it a desirable material to use in device applications. Moreover, magnetic calculations which extracted from dielectric impedance spectroscopy measurements, are also investigated. The complex magnetic permeability and also magnetic loss curves are plotted. Eventually, the study of the magnetic properties using VSM showed room-temperature ferromagnetic behavior.