Structural, dielectric, and magnetic properties of nickel rich manganese substituted Li2Ni6MnxCo2-xO10 nanomaterial synthesized via sol-gel method

Abstract

Manganese-substituted nickel-rich lithium-cobalt oxide Li2Ni6MnxCo2-xO10 was synthesized via the sol-gel auto-combustion method. The structure and morphology were investigated respectively by X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) technique. Hexagonal structure was confirmed by XRD pattern with secondary phase. The crystallite size of the prepared nanomaterial was determined by modified Scherer modified (MSM), size-strain plot (SSP), and Williamson-Hall (W–H) method approaches. The average crystallite size has been correlated for each method and found to range from 12 to 27 nm. SEM was performed to investigate the surface morphology, particle size, and their distribution. The dielectric characteristics have been investigated with the effect of applied frequency in the range of 1 MHz–3 GHz. Synthesized material's dielectric characteristics such as impedance, electrical conductivity, modulus, and dielectric constant have been studied and found frequency dependent. Sensitivity response at high frequency suggested that the material is applicable for high-frequency devices. Magnetic measurements were made using M − H loops of coercivity (Hc), saturation magnetization (Ms), and retentivity (Mr). Both saturation magnetization and coercivity varied with increasing Mn concentration. The maximum value of Ms found at x = 0.50 and subsequently decreases with increasing Mn-content. Prepared samples are soft magnetic materials due to low coercive field. Further, the obtained dielectric properties suggested that the prepared materials can be used for energy storage applications.