Dielectric and magnetic properties of dilute magnetic semiconductors Ag-doped ZnO thin films

Abstract

Ag-doped ZnO thin films are prepared by the cost-effective sol–gel dip-coating method at room temperature. The Ag dopant percentage varies between (2–10) wt%. The magnetic and dielectric properties have been studied. The dielectric and magnetic properties of ZnO are significantly tailored by the increase in the Ag doping percentage. High dielectric constant and tangent loss have been observed at low frequencies which decreases with the increase in frequency. The AC conductivity is lower in the low-frequency region but has larger values in the high-frequency region. The ferromagnetic behavior of films has been recorded at room temperature. Magnetic polarons play a pivotal role in the development of room temperature ferromagnetism in Ag-doped ZnO thin films. So, ferromagnetism in thin films is governed by bound magnetic polarons. As the doping concentration increased, the saturation magnetization decreased and coercivity increased due to the combined effect of the decrease in crystallite size, generation of large defects, and formation of bound magnetic polarons. These Ag-doped ZnO thin films are suitable for spintronics.