Resistivity enhancement in c-axis-grown nanograin Mn–Zn ferrite thin films generated through radio frequency sputtering technique

This article delves into the resistivity enhancement observed in c-axis-grown nanograin Mn–Zn ferrite thin films, focusing on the conduction mechanisms and the influence of zinc concentration. The study employs radio frequency (RF) sputtering to deposit these films on quartz substrates, followed by a thorough structural characterization using X-ray diffraction (XRD) and Raman spectroscopy. The temperature-dependent resistivity of the films is measured using a custom-built four-probe resistance measurement system, revealing a significant increase in resistivity compared to the target materials. The article explores the impact of zinc concentration on the resistivity, attributing the observed enhancement to reduced charge carrier mobility due to perpendicular grain boundaries formed during c-axis film growth. The study also discusses the Verwey–de Boer mechanism to explain the charge carrier mobility in these materials. The findings provide valuable insights into the electrical properties of Mn–Zn ferrite thin films, highlighting the importance of structural and compositional factors in determining their resistivity.