الفهرس | Only 14 pages are availabe for public view |
Abstract Due to their technological applications, nanocrystalline ferrites, especially spinel nanomaterials, have evoked greater interest in this decade. The investigation of the properties of doped nano ferrites helps to improve their performance and make their applications more diverse. The demand for high-performance devices is an important step towards synthesizing the investigated samples in nanoscale form. The lithium cobalt spinel ferrite with the general formula Li1.1Co0.3Fe2.1O4 is a low-cost material which is generally useful for numerous applications. In the present study, we have synthesized the Li1.1Co0.3Fe2.1O4 ferrite nanoparticles by using the citrate auto combustion method. The distribution of cations on A-site and B-site is studied by X-ray diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Field emissionscanning electron microscope (FESEM), Atomic force microscopy (AFM), and Raman Spectroscopy. In addition, X-ray photoelectron spectroscopy (XPS) is carried out to identify the various ions existing in samples and their oxidation states. The XRD study confirms that prepared nanoparticles are cubic spinel structures having an Fd3m space group and the crystallite size is approximately 36 nm. The magnetic hysteresis loop has been studied by the Vibrating Sample Magnetometer. The samples have less magnetization because the magnetization of the Asublattice becomes much diluted, and the A-B exchange interactions become weaker or comparable to the B-B exchange interactions. Consequently, the canted spins and the Yafet–Kittel (Y–K) angle are increased. Additionally, it can also be owed to the formation of an inactive magnetic layer and the disordered cation distribution. VII The electrical conductivity as well as the dielectric constant were recorded as a function of frequency and temperature. The resistivity mechanism of humidity sensors is studied via complex impedance spectroscopy (CIS). Its impedance data is fitted to a corresponding circuit to achieve a simulation of the sample under study. This fitting is detected by the Nyquist plot (ColeCole). The obtained data confirms that the studied samples are very sensitive to humidity and can be commercially used as a humidity sensing element. The Li1.1Co0.3Fe2.1O4 has also been employed as a sorbent material for the removal of lead (II) ions from wastewater. Two models of adsorption isotherms (Freundlich and Langmuir) are utilized to recognize the adsorption mechanism. Finally, this work is focused on some of the critical issues of investigating nanoparticles as active materials in Li-ion batteries, namely, electrode preparation, nanoparticle synthesis, and electrochemical characterization. The cyclic stability was scrutinized via galvanostatic charging/discharging (GCD) and electrochemical impedance spectroscopy (EIS). Its purpose is to act as a reference for future work in this area. |