Role of dysprosium in enhancing the humidity sensing performance in manganese zinc ferrites for sensor applications

In the present scenario, ferrites are widely used for humidity sensor applications. Aiming this, we have prepared Dy³⁺-doped Mn–Zn ferrites by solution combustion method combining urea and glucose as burning agent. And obtained powder was characterized by several physicochemical techniques. The phase purity was confirmed by using the techniques such as X-ray powder diffraction and infrared spectroscopy. FTIR spectra show 2 prominent absorption bands under 1000 cm⁻¹ which confirms the formation of spinel ferrite. The dielectric studies with change in frequency exhibited remarkable changes with Dy³⁺ content in samples. All electrical responses were investigated as a function of frequency and Dy³⁺ content at room temperature. The dielectric constant and loss on the frequency of the alternating applied electric field is consistent with Maxwell–Wagner style interfacial polarization. Further Humidity sensing response were recorded for pellet samples. It is noteworthy that, as the composition of the Dysprosium (Dy³⁺) increases the resistance is enhanced and is maximum for the Mn_0.5Zn_0.5Dy_0.03Fe_2−0.03O₄ composite. Hence our results are good enough for sensor applications.