The manuscript investigates the structural and morphological characteristics of thin films of calcium stabilized zirconia (CSZ, 16 mol % CaO), synthesized through electron beam deposition on silicon wafers, with a focus on the phase evolution during annealing at 800 degrees C. The study compares these properties with yttria stabilized zirconia (YSZ, 8 mol % Y2O3) thin films. Rutherford backscattering spectrometry validates film composition, with thicknesses of similar to 315 nm for CSZ and similar to 285 nm for YSZ. X-ray diffraction initially identifies an amorphous structure, transitioning to a cubic phase post-annealing, with average crystallite sizes of 18.07 nm for CSZ and 16.22 nm for YSZ, corroborated by Raman spectroscopy. The lattice parameters are determined using Rietveld refinement. Surface morphology is investigated through field emission scanning electron microscope and atomic force microscopy shows a reduction in surface roughness from 6.05 nm to 1.34 nm for CSZ and from 4.54 nm to 1.64 nm for YSZ post-annealing, indicating enhanced homogeneity. Elemental distribution analysis using energy dispersive X-ray spectroscopy confirms film uniformity. The study provides insights into the structural evolution and morphological characteristics of calcium stabilized zirconia thin films, particularly at the nanoscale level, offering valuable contributions to its industrial applicability.

Super Absorbent Polymers (SAPs) are the new type of three-dimensional macro cross-linked hydrophilic polymers, which swell without dissolving on contacting with water or other biological fluids and by osmosis, will uptake about 100,000% of its own weight in a short span of time. In the soil, they form granules to enhance its properties and for slow release of agrochemicals. The various characteristics of these super absorbent polymers overcome the problems related to the degradation process, environmental and health issues. This chapter would prove to be a comprehensive review on various SAPs (natural and synthetic), their properties, preparation techniques, modification with specific functions and their applications with remarkable advantages in agriculture sector. Here the emphasis is given to the two key applications of SAPs, i.e., water absorbance and retention and as control release devices for agrochemicals. The future developments of SAPs have also been discussed in this chapter for providing a background for their amazing properties/performance in the field of agriculture.

The homogeneous zirconia thin films having a thickness of 250 nm synthesized on silicon substrate using an e-beam deposition technique and annealed in the temperature range of 600-1000 degrees C have been investigated for phase transformations of zirconia. It has been observed from the X-ray diffraction (XRD) pattern and the Raman spectroscopy that phase transformation from cubic phase to monoclinic phase of zirconia occurred in the temperature range 600-800 degrees C, despite the amorphous nature of deposited films. From Rietveld refinement studies, it has been found that crystalline phase in zirconia films annealed at 600 degrees C, is cubic in nature. Further, the morphological studies revealed that the grain size of zirconia increases with an increase in the annealing temperature. It is expected that the present studies on structural and morphological properties of zirconia having an emphasis on its cubic phase stabilization shall help to explore its possibility in device applications.

The phase evolution studies of 16 mol% calcium-doped zirconia have been carried out after sintering the samples at 800 °C, 1000 °C, 1200 °C, and 1400 °C. The X-ray diffraction (XRD), Raman spectroscopic along FTIR studies confirmed that the pure zirconia exists only in the monoclinic phase. However, the XRD analysis of calcium-doped zirconia and its Rietveld refinement studies revealed the stabilization of zirconia in the monoclinic and cubic phases both. With increasing sintering temperature, the development of cubic phase in zirconia is seen and at 1400 °C, an almost fully stabilized cubic phase of zirconia is achieved. The traces of CaZrO3 (perovskite phase) are observed in XRD and Raman studies when samples are sintered at 800 °C and 1000 °C. The results of FESEM suggest that grains are uniformly distributed and closely packed. Further, EDS mapping suggests that the calcium is uniformly distributed in samples. The thermal stability analysis confirms that calcium-stabilized zirconia is stable at high temperatures and analysis of the Vickers hardness test confirms that it is harder as compared to pure zirconia. Results reported here indicate that the sintering of 16 mol% calcium-doped zirconia at 1400 °C leads to the complete transformation of m-ZrO2 to c-ZrO2.

The phase transformations induced in zirconia thin films by irradiating with 1.4 MeV Kr ion-beam have been investigated. The films as-deposited and annealed at 800 °C, synthesized by using the e-beam deposition method, are bombarded with ion fluences of 7e14, 1e15 and 3e15 ions/cm2, respectively. The modifications in the structural and morphological properties have been observed in both cases. The as-deposited film showed an amorphous nature in XRD analysis and the evolution of cubic phase with the increase in fluence of irradiation, while the film annealed at 800 °C confirm the development of monoclinic phase along with a fraction of cubic phase which transforms into a cubic phase with an increase of fluence of irradiation. The surface features captured by FESEM, and AFM reveals the grain agglomeration and grain boundary diffusion with increasing fluence. These studies shall contribute to realize the large-scale production of cubic stabilized zirconia films for various industrial applications.

In this work, the target of zirconia with 2-inch diameter is prepared from the powder form having a particle size 5 µm by giving 4 tonnes of pressure in the hydraulic press. The prepared target is sintered at 1000-degree Celsius for 10 hrs. Yttria-stabilized zirconia target is also obtained in a similar process. The structural properties of both targets are investigated using Ɵ-2Ɵ geometry of X-ray diffractometer system. The changes in structure are studied in doped and undoped zirconia. The structural findings are showing the transformation of phase with doping. These studies help to understand the structural properties of zirconia with and without doping for technological application.

Zirconia (ZrO2) has a unique property of changing the crystalline phase from monoclinic to cubic at a higher temperature. This leads to its versatile applications in the fields of nuclear reactors, oxygen detectors, solid oxide fuel cells etc. Yttria doped zirconia has been studied extensively for transformation and stabilization of its cubic phase at room temperature. Whereas, the reports on such accounts with calcium doping are rare. In present study, the crystalline structure of Ca-doped zirconia (8 mol % Ca) as prepared by the solid-state reaction technique and sintered at 1000 °C in air, is compared with that of pure zirconia. From the X-ray diffractometer patterns recorded in θ-2θ geometry, it is evident that the pure zirconia exists only in the monoclinic phase. Further, the XRD of Ca-doped zirconia and its Rietveld refinement revealed the stabilization of zirconia in the monoclinic and cubic phase. The cubic phase stabilization in zirconia at room temperature with calcium doping opened up the possibilities of tailoring its properties more precisely via ion implantation.

The phase evolution studies of zirconia, with 4-16 mol-% doping of calcium, have been carried out after sintering the pellets at 1400 degrees C. From the X-ray diffractometer patterns, it is evident that the zirconia exists only in the monoclinic phase. However, Rietveld refinement of calcium-doped zirconia revealed the stabilisation in the monoclinic and cubic phases. With increasing calcium doping, the development of the cubic phase in zirconia is seen and at 16 mol-% doping of calcium, almost fully stabilised cubic phase of zirconia (similar to 97%) is achieved. The microstructure and elemental analyses of the sintered pellets are done using a field-emission scanning electron microscopy and energy-dispersive spectroscopy, respectively. Raman spectroscopic studies validate the findings of XRD. It is expected that the present study on calcium-doped zirconia opened a new channel for its potential applications in new technology such as oxygen sensors and solid electrolyte.

Dye-Sensitized Solar Cells (DSSCs) are the promising low-cost solar cells to convert solar energy into electric energy. In this study, TiO2 based Dye-Sensitized Solar Cell is fabricated. TiO2 paste is prepared by using ethanol as a solvent. A thin layer of TiO2 paste is coated on ITO conducting glass, which acts as a working electrode. The counter electrode is prepared by pencil graphite paste using ethanol as a solvent and coated on ITO conducting glass. The dye solution is prepared by adding commercially available methylene blue dye to ethanol and deionized water. From XRD studies, the average crystallite size of TiO2 powder is found to be 88.46 nm. This indicates that the nanostructure of the TiO2 having a large surface to volume ratio playing a vital role in the absorption of solar radiations by the material. J-V characteristics of fabricated DSSC were studied to evaluate its performance in terms of a short circuit current, open-circuit voltage, and fill factor. The performance of DSSC may be enhanced by decreasing the crystallite size of TiO2.