Synthesis and characterization of non-stoichiometric Li1.1Co0.3Fe2.1O4 ferrite nanoparticles for humidity sensors
Mahmoud A. Ateia, Ebtesam E. Ateia, Mohamed Mosry, M. M. Arman
Abstract
Abstract A humidity sensor plays a crucial role in determining the efficiency of materials and the precision of apparatuses. To measure and control humidity, a non-stoichiometric Li 1.1 Co 0.3 Fe 2.1 O 4 mesopore sensor is synthesized by a modified citrate auto combustion technique. The XRD study confirms that prepared nanoparticles are cubic spinel structures having an Fd3m space group. The crystallite size is approximately 36 nm. Thermal analysis measurements show that samples become thermally stable at a temperature of 600 °C. Additionally, the kinetic studies of the prepared samples are calculated via a pseudo-first-order kinetic model. The temperature dependence of AC conductivity is found to increase with increasing temperature. These observations are explained in various models. The resistivity mechanism of humidity sensors is studied via complex impedance spectroscopy (CIS). Its impedance data are fitted to a corresponding circuit, to achieve a simulation of the sample under study. This fitting is detected by the Nyquist plot (Cole–Cole). The obtained data confirm that the studied samples are very sensitive to humidity and can be commercially used as a humidity sensing element. Graphical abstract