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Microstructure and Magnetic Properties of Nano Crystalline Manganese Ferrite Thin Film Fabricated by Pulse Laser Deposition
(American Scientific Publishers, 2016) Jaison, Joseph,; Tangsali, R. B; Mahadevan Pillai, V. P.; Choudhary, R. J.; Phase, D. M.; Ganeshan, V
Nanoparticles of Mn Fe2O4 were chemically synthesized by precipitating the metal ions in aqueous alkaline solution with due optimization of reaction parameters. The XRD data of the powder sample comprising all prominent spinel peaks and clear visibility of ferrite absorption bands in FT-IR spectrum confirm single phase spinal formation. Nano grain size values of the sample derived from XRD data is authenticated by particle size viewed in TEM micrograph. Thin film fabricated from this nano material on quartz substrate by pulse laser deposition technique was characterized using XRD and Raman spectroscopic techniques. The XRD results of fabricated thin film indicate moderate degree of texture. AFM image of the thin film showed nano granular morphology with spherical particles of regular size and uniform distribution. Particle size analysis of AFM data suggest formation of thin film by near uniform clustering of nano grains whose dimensions match that of target material. Magnetic measurements of the textured nanocrystalline ferrite thin film revealed enhancement of magnetic properties. The enrichment of coercivity is explained on the basis of large magnetic anisotropy formation in thin film due to texture enhanced lattice strain and surface disorder.
Synthesis, Structural and Morphological Property of BaSnO3 Nanopowder Prepared by Solid State Ceramic Method
(IOP Publishing Ltd., 2017) John, Jibi; Mahadevan Pillai, V.P; Thomas, Anitta Rose; Philip, Reji; Joseph, Jaison; Muthunatesan, S.; Ragavendran, V.; Prabhu, Radhakrishna
Characterization and optical limiting behavior of BaSnO3 powder prepared by the conventional solid state method
(Elsevier Ltd, 2020) John, Jibi; Chalana, S.R.; Mahadevan Pillai, V.P.; Joseph, Jaison; Muthunatesan, S.; Ragavendran, V.; Tiwari, Gargi
BaSnO3 powder was prepared by the conventional solid state ceramic method. The structural, morphological, thermodynamical and non linear optical properties of the prepared powder were studied using techniques such as XRD, SEM, TEM and photoluminenscence spectra. XRD analysis reveals, that the prepared powder is polycrystalline in nature with cubic BaSnO3 phase. SEM and AFM analysis also support the XRD analysis. The optimized structure and the comparison of FT-IR and FT-RAMAN spectra were done. The thermodynamical property of the prepared sample was measured. Photoluminenscence spectrum reveals that there is an intense red emission in the visible region. The thermodynamic functions like enthalpy, entropy and heat capacity were found to increase with increasing temperature. There is an optical limiting behavior for the sample which is comparable to that of graphene and its metal hybrids.
Swelling and DC Conductivity Behaviour of Gelatin-Based Ferrogels
(Springer Nature, 2021) Lawrence, Mathias B.; Joseph, Jaison; Usapkar, Twinkle; Azavedo, Firman
Gelatin-based systems have great potential in bio-medical applications. Here, we report the solvent uptake and DC conductivity of glutaraldehyde-crosslinked gelatin hydrogels and ferrogels. Both the parameters are found to depend on cross-linker (glutaraldehyde) and dopant (carbonyl iron) concentrations. Higher cross-linker proportions cause decrease in solvent uptake, equilibrium swelling ratio and DC conductivity. Solvent uptake is seen to increase while equilibrium swelling ratio and DC conductivity decrease with dopant concentration in the ferrogels. The solvent uptake and DC conductivity behaviour of the studied systems are explained on the basis of variations in pore size and polymer segmental mobility which, themselves, are functions of cross-linker and dopant concentrations. The diffusion process in the hydrogels and ferrogels obeys the second-order kinetic model.
Spectroscopic, thermal and sorption characterization of poly(vinyl alcohol)-borax hydrogels with incorporated turmeric
(Springer Nature, 2025) Lawrence, Mathias B.; Joseph, Jaison
In this work, three sets of poly(vinyl alcohol) hydrogels, cross-linked using borax, with incorporated turmeric have been synthesized. Their water content, spectroscopic, thermal and sorption properties have been studied, as functions of borax and turmeric concentrations. The water content of the hydrogels decreases due to the presence of turmeric. The Fourier Transform Infra-red (FT-IR) and Raman spectroscopic measurements confirm the incorporation of turmeric in the matrices. Turmeric does not chemically bond with the polymer hydrogel network but is confined to the solvent phase within the pores. The presence and concentration of turmeric significantly affect the adsorption of water molecules onto the polymer backbone. Glass transition temperature and solvent uptake are affected by the concentration of borax and turmeric in the matrices. The sorption behaviour obeys the second-order kinetic model. The observed modifications in properties are caused by the structural re-arrangement of the polymer chains and the re-organization of borate cross-links due to the presence of turmeric.