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In this work, pure and Mn-doped nickel ferrite (Ni1-xMnxFe2O4, x = 0, 3, 6, 9, and 12 wt%) thin films were prepared using facile nebulizer spray pyrolysis technique. The effect of Mn concentration on the structural, optical, and magnetic properties was studied. The XRD pattern confirms the cubic spinel structure of Ni1-xMnxFe2O4 thin films and reveals the preferred orientation along the (311) direction for each film. Moreover, the average crystallite size (D) is found to increase from 13 to 30 nm with increasing Mn concentration. The FESEM micrographs exhibit randomly arranged plate-like and rice-like grains. The elements such as Mn, Ni, Fe, and O are confirmed by the EDX analysis. The optical band gap energy (Eg) varies between 2.90 and 3.60 eV. The Ni1-xMnxFe2O4 film prepared with 3 wt% of Mn exhibits superior ferrimagnetic behavior with the highest value of ηB (57.31) due to the high crystallinity, packing density, and smooth surface of the film. The present work shows that the facile nebulizer spray pyrolysis technique can produce high-quality Ni1-xMnxFe2O4 thin films with good magnetic properties.

In the present study, the wear resistance behavior and the microhardness of the Co38Ni35Al27 and Co35Zn10Ni32Al23 ferromagnetic shape memory alloys (FSMAs) were investigated. The alloy samples were prepared by powder metallurgy method along with the vacuum sintering technique. The major aim is to prepare an alloy with high wear resistance having remarkable microhardness suitable for the sustainable shape memory alloy. The wear test report shows that the wear resistance is high for the sample sintered at 673 K and it gradually reduces when the sintering temperature decreases. The result also shows that the inclusion of zinc in the alloy increases the wear rate. The maximum hardness value of 126 HV was observed in Co38Ni35Al27 sample sintered at 673 K for 8 hrs because of its minimal porosity.

In this work “solve two problems with one single action” strategy was implemented for degradation of industrial dye Amaranth and enhanced blue-green emission for opto-electronics applications in Cu2+ doped ZnO materials. The different concentrations (weight (wt) %) of Cu2+ doped ZnO materials have been synthesized by the thermal spreading method. The as-prepared ZnO and Cu2+ doped ZnO materials have effectively confirmed by various spectroscopic methods. The crystalline phase, surface morphology, compositions of elements and energy bandgap were studied systematically enquired by PXRD, SEM, EDS and UV-vis spectroscopic analysis, respectively. With the dopant concentration, 18 wt% of Cu2+ doped ZnO revealed outstanding photocatalytic performance to the degradation of Amaranth under visible light irradiation with an efficacy of about 97%. Likewise, 18 wt% of Cu2+ doped ZnO shows an strong blue-green emission at around 495 nm owing to the internal oxygen vacancies. The present work gives some clue; it may be used as a proficient photocatalyst for degradation of dyes and luminescent material for optoelectronics applications.

Co38Ni35Al27 and Co35Zn10Ni32Al23 ferromagnetic shape memory alloys were prepared via facile powder metallurgy and vacuum sintering technique. The influence of sintering temperature on phase transformation behaviour, microstructure and magnetic properties were investigated. The rise in peak intensity of A2-phase shows that the alloy is rich in martensitic-phase in the polycrystalline cubic B2-phase structure and Zn incorporation leads to the reduction in austenite-phase. The needle-shaped cobalt precipitates on predominant martensite A2-phase, shows Widmanstatten-like structure in the samples sintered at 673 K. The saturation magnetization was found to be 87.92 and 96.2 emu/g for Co38Ni35Al27 and Co35Zn10Ni32Al23 alloy. The existence of non-interacting single-domain particles were observed and proved using Stoner-Wohlfarth model.

Co-Ni-Al alloy samples were prepared by compacting the powdered alloy at various pressures in proper stoichiometric ratio and the high density compacted alloy was sintered at 673 K. The magnetic, mechanical properties, microstructure and phase analysis were studied and compared with that of spark plasma sintered (SPS) alloy. The sintered alloy exhibit martensitic twin variants with ? phase structure. Along with the diffused particle, few agglomerated clusters were observed on the topographic images. The magnetic and the mechanical studies of the test specimens were investigated using the vibrating sample magnetometer, pin on disk tribometer and universal testing machine respectively. The coercivity value and the ductility of the SPS alloy are higher than the same of the as-sintered alloy.

Synthesis of metal chalcogenides nanostructures is of profound importance in obtaining desired properties for photo-sensing device fabrication. The present proposed work concentrates on the effect of oleic acid in the preparation of NiS and SnS/NiS composites, and their photodiode properties were examined. Synthesized NiS and SnS/NiS nanosystem characterized by XRD analysis, Raman analysis, Field Emission Scanning Electron Microscopy micrographs. Hexagonal structure of NiS and hexagonal and orthorhombic composite structures SnS/NiS composite was confirmed with XRD patterns. The single-phase SnS nanoparticle and SnS/NiS nanocomposite were confirmed with Raman analysis. The change in morphology while increasing oleic acid on the preparation of NiS and SnS/NiS as aggregated quasi sphere structures were verified with FE-SEM micrographs. SnS/NiS fabricated with different ratios, and oleic acid-assisted NiS composite particles show better photo-response, which is essential for photodiode application.

Co–Ni–Al is considered as a suitable ferromagnetic shape-memory alloy and has significant control over structural transformation temperature, magnetic parameters, and ductility. In this paper, the fabrication of Co–Ni–Al alloy thin films on Si (1 0 0) substrate was achieved via pulsed laser deposition (PLD) technique. The developed films annealing was done at 573, 673, and 773 K temperatures and inveterate their crystalline structure, phase analysis, and magnetic nature of the annealed Co38Ni35Al27 films. X-ray diffraction analysis at 773 K annealing temperature reveals that, the Co38Ni35Al27 film shows high crystallinity, and all annealed films have a body-centered cubic phase structure. The crystallite size estimated from Scherrer rule is noticed to increase from 10 to 22 nm when the annealing temperature raised to 773 K. From the SEM images, we infer that there is an increase in grain size when the annealing temperature increases and the grains shape looks spherical. The magnetic study of the samples shows that the film possesses highest magnetic saturation and lowest coercivity at 773 K annealing temperature. Also, the film annealed at 773 K exhibits a wide range of transformation temperatures and has a curie temperature of 180 K.

The CoNiAl alloys are prepared by using the spark plasma sintering (SPS) technique. The present study investigates the crystalline structure , Phase analyses, Physical and mechanical properties of the stoichiometric Co38Ni35Al27 alloys. The significant control over the magnetic and structural transformation temperature and high ductility of CoNiAl makes it a potential high-temperature Ferromagnetic shape memory alloy (FSMA). The test specimens were prepared at SPS temperature of 1000 °C at a sintering pressure of 50 MPa. The microstructural identification and the phase analyses of the mechanically alloyed powders and the SPS sintered specimens were investigated using optical microscopy, scanning electron microscopy and X-ray diffraction. The room temperature XRD results revealed that the sintered samples have body centred cubic β phase. A comparison of the room temperature XRD results for alloy powders and that of the sintered alloys has been studied. From the SEM images, we observe that the sintered alloys have martensitic twin variants. Also in the optical microscope, we observe the martensitic variants in the β phase structure. From the thermal studies, we analysed the phase transformation behaviour of the sample from β’ martensite to β martensite at 120°.