Faculty Publications
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Item Investigation of structural, thermal, magnetic, and dielectric properties of Yb+3 doped nickel cobalt ferrite nanomaterial for electro-magnetic applications(Springer, 2024) Patil, S.; Meti, S.; Anandalli, M.; Badiger, H.; Bhajantri, R.F.; Pratheek, L.; Muhiuddin, M.; Rahman, M.R.; Hegde, B.G.Herein, we report the synthesis of ytterbium (Yb) (with concentration x = 0.01, 0.015, 0.02, 0.025 and 0.03) doped in to nickel cobalt ferrite (NCYFO: YbxNi0.5Co0.5Fe2-xO4) nanoparticles at temperature 500 °C with phase pure spinel using solution combustion technique. The phase purity and effect of doping on NCYFO complex oxide on structural, thermal, magnetic and dielectric properties have been determined by various characterization techniques. The FTIR data reveal that strong metal oxide linkages can be observed in the tetrahedral and octahedral sites at wavenumbers 460 to 410 cm−1 and 595 to 540 cm−1. The X-ray diffraction (XRD) studies confirmed the spinel structure. The crystallite sizes and lattice parameters were estimated to be in the range of 31 to 22 nm and 8.32 to 8.35 Å, respectively. The X-ray photoelectron spectroscopy (XPS) study confirmed that the increase in Yb concentration results in accumulation of Yb in the grain boundaries of NCYFO in the form of Yb2O3. The thermal stability of nanoparticles were investigated using TGA/DSC method. Transmission Electron microscopy (TEM) studies and Field emission scanning electron microscopy (FESEM) used to study the particle size distribution and elemental composition within the nanomaterial. In addition, the dielectric properties, such as, dielectric constant and dielectric loss were investigated for all the NCYFO nanomaterial. The saturation magnetization of the NCYFO is determined using vibrating sample magnetometer (VSM) analysis and is maximum for x = 0.03 (Ms = 97.56 emu/g) sample. The high magnetic behaviour and better dielectric properties of the NCYFO nanomaterials are suitable for electro-magnetic applications. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.Item The cohesion strength of electrodeposited Zn/GO nanocomposite coating on stainless steel(Elsevier Ltd, 2025) Bharathi, K.D.; Udaya Bhat, K.; Bhat Panemangalore, P.; Arun Kumar, D.S.; Rahman, M.R.Graphene based nanocomposite coatings have incredible scope in enhancing the physical properties of composite materials. In this study, pure Zn and Zn/GO nanocomposite coatings were successfully prepared by electrodeposition technique on the SS304 stainless steel. The Zn/GO nanocomposite coatings were prepared by varying concentration of GO, coating time and CTAB ratio. The nanocomposite coatings were characterized by using the Field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), Energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. Cohesion strength (LC) using scratch test at RT noticed that the LC values increased with the concentration of GO. The scratch tests revealed that Zn/GO composite produced using 40 mgL?1 GO had 70 % increase in cohesion strength (LC1) in comparison to pure Zn coating deposited with 30 min of coating time at a ratio of 1:2 GO:CTAB. The magnitude of the residual stress in the nanocomposite coating decreases from ?32 MPa (0 mgL?1 of GO) to ?11 MPa (40 mgL?1 of GO) as the GO concentration increases in coatings due to the effect of the kinetic movement of particles while deposition. © 2024Item Synthesis and characterization of N-doped reduced graphene oxide for the supercapacitor application(Springer, 2025) Moodakare, R.; Sahoo, B.; Bharadishettar, N.; Rahman, M.R.; Muhiuddin, M.; Udaya Bhat, K.In this work, N-rGO is synthesized as a material for the electrode of supercapacitors using a single-stage hydrothermal process. Ammonia functions as a nitrogen source and a reducing agent, significantly enhancing its electrochemical properties. X-ray diffractometry (XRD), Raman spectroscopy, field emission gun scanning electron microscopy (FESEM), and FT-IR (Fourier-transform infrared spectroscopy) were employed for characterization of as-prepared N-rGO electrodes. The XRD plot evidences the successful reduction of as-received GO to as-prepared N-rGO. The FESEM micrograph displays the formation of highly porous and multi-layered N-rGO, showcasing significant structural characteristics. The nitrogen atoms are successfully incorporated into the resulting material (N-rGO) and have been verified through EDS and FT-IR spectroscopy studies. The specific capacitance of N-rGO reaches 107 Fg?1 at 0.5 Ag?1 in a 0.5 M H2SO4 aqueous electrolyte solution. The electrodes showed exceptional cyclic performance, maintaining approximately 130% capacitance after 10,000 cycles and delivering steady Coulombic efficiency. The material's porous structure and nitrogen doping create abundant active sites, facilitating electrolyte ion migration and producing exceptional capacitive performance. The electrochemical impedance spectroscopy study revealed that the N-rGO exhibited a distinctive capacitive behavior. The synthesized N-rGO offers excellent potential for an efficient energy storage application due to its simple, cost-effective, and eco-friendly approach. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.