Materials Science: A Field of Diverse Industrial Applications

Chalcogens are the chemical elements of group 16 of the periodic table. Oxygen is treated separately from other chalcogens; it is even excluded from the term ‘chalcogen’ altogetherdue to its very different chemical behaviour from sulfur, selenium, tellurium and polonium. The heavier chalcogens have vacant d orbitals. A chalcogenide consists of at least one chalcogen element and one electropositive element. The term chalcogenide is more commonly reserved for sulfides, selenides and tellurides rather than oxides. The interest in these materials arises particularly due to their ease of fabrication in the form of bulk and thin films. Generally, chalcogenides have a large glass-forming region and thus, their physical properties can be tuned via chemical composition. These glasses have drawn great attention due to their striking electrical, optical and thermal properties, which ary with composition, heat treatment, irradiation, glass forming methods, etc. There is a high tendency for the atoms to link together to form link chains in chalcogenides. In general, the atomic bonding is more rigid than that of organic polymers and more flexible than that of oxide glasses. This chapter presents the method of fabrication of chalcogenides in bulk and thin film forms.

During the last two decades, by using a combination of both chalcogens (sulfur (S), selenium (Se), tellurium (Te), and polonium (Po)) and other elements like silicon (Si) and germanium (Ge), a huge number of chalcogenide glasses (ChGs) were prepared and studied. Compared to oxide-based glassy materials, ChGs have unique properties and functionalities which make them suitable for photonic applications. These materials are transparent in nature from the visible to the near-infrared region and can be used for the preparation of optical and electronic devices like ChG fibers, optical switches, sensors, and phase change memorizers. This chapter deals with some basics of ChGs, preparation techniques and a review of the latest technological development. The structural properties, optical properties, thermal and electrical properties of ChGs have been discussed. The physical aging effect has been explored. In the second part of this chapter, the applications of ChGs especially in dye sensitized solar cells (DSSCs), semiconductors, electrical memories and phase change memories have been discussed.

In the last three decades, Zinc oxide (ZnO) has been found to be one of the most resourceful materials having tremendous potential applications in manifolds covering a wide variety of areas. It is continuously explored in different forms and structures. ZnO-based layers have an established place in the industry that ranges from protecting degradable items to detecting toxic gases. A wide variety of ZnO-based advanced coatings and their surface treatments along with innovative functionalization technologies offer a multitude of options for making them useful in diverse industries. Multiple techniques ranging from exceedingly sophisticated ones like molecular beam epitaxy and atomic layer deposition to highly-cost effective ones like sol-gel spin coating and dip coating, etc. have been used for developing the ZnO based thin films. Doping suitable elements into ZnO matrix is the most promising strategy to alter its properties drastically. Out of numerous dopants, Aluminum (Al) offers some of the excellent and reproducible features in ZnO films which make Al doped ZnO (AZO) a reputable system in industries like thin film transistor manufacturing and solar cells. Specifically, its established and repeatable behavior in terms of transparency and conductivity becauseis finding huge applications as a transparent conducting oxide (TCO). Extensive research on AZO coatings derived from different methods day-b-day opens up a new gateway for interesting perspectives by optimizing surface nanostructures. Here a brief account of historical developments of ZnO to AZO films along with their applications in certain key areas like TCOs, solar cells, thin film transistors, flexible electronics and plasmonics, etc. is presented.

Man-made fibres are produced from chemical substances known as synthetic fibres. Synthetic fibre or a synthetic polymer made from molecules of monomer joined together to form long chains, is also known as an artificial fibre. Besides polymerbased synthetic fibres, other types of fibres that have special commercial applications and importance. These include the fibers made of carbon, glass,metal and ceramics. Polymer-based synthetic fibres are produced by various processes such as melt spinning, dry spinning and wet spinning.
The melt spinning technique is used to produce polymers such as polyethene, polyetheneterephthalate, cellulose triacetate, polyvinyl chloride, nylon, etc. Cellulose acetate, cellulose triacetate, acrylic, modacrylic, polyvinyl chloride and aromatic nylon are artificial fibres manufactured by dry-spinning. In contrast, the wet spinning process is used for aromatic nylon, polyvinyl chloride fibres, acrylic, modacrylic and viscose rayon from regenerated cellulose.
The importance and usefulness of synthetic fibres are because they have enhanced properties compared to natural fibres, which come from plants or animals. Still, each type is valued for different reasons.

BaF2 thin films of thickness 20 nm are prepared using the electron beam evaporation technique (at room temperature) on glass, silicon (Si) as well as aluminum (Al) substrate, respectively. These substrates play a crucial role in the evolution of thin film surface morphology. The thin films grown far from equilibrium have self-affine nature which is reminiscent of fractal behaviour. The surface morphology of films is recorded by atomic force microscopy (AFM). Scaling law analysis is performed on AFM images to confirm that the thin film surfaces under investigation have self-affine nature. The concept of fractal geometry is applied to explore-how different substrates affect the surface morphology of films. The fractal dimension of horizontal as well as vertical sections of AFM images are extracted by applying Higuchi’s algorithm. Value of Hurst exponent (H) for each sample is estimated from fractal dimension. It is found to be greater than 0.5 for Al as well as glass substrates, indicating that the height fluctuations at neighboring pixels are correlated positively. However, for Si substrate, its value is less than 0.5 which suggests that the height fluctuations at neighboring pixels are not positively correlated.

Observation of at least two coexisting switchable ferroic states viz., ferromagnetic, ferroelectric, and/or ferroelastic at room temperature with promising coupling among order parameters, has made BiFeO3 a highly explored material in the field of multiferroics and/or magnetoelectric multiferroics, which creates the possibility for its application in various technological devices such as spintronics, spin-valve, DRAM, actuators, sensors, solar-cells photovoltaic, etc. Intrinsically, its low coupling coefficients, difficulty to prepare in pure phase in bulk, high leakage current, etc. have restricted BiFeO3 from technological reliability. However, the effect of doping with iso- and alio-valent ions, nanostructure, thin-film-form and nanoparticles, etc., has been carried out to improve its physical properties by several research groups over the decades. In this chapter, the structural, luminescence, and dielectric properties of samarium (Sm3+) doped BiFeO3 nanoceramics synthesized using a modified gelcombustion route are discussed in detail. The effect of Sm3+ doping in BiFeO3 is explored using the X-ray diffraction (XRD) technique. The XRD studies exhibit a possible structural phase transition above Sm3+ doping of 15% from rhombohedral (R3c) space group to the orthorhombic (Pbnm) space group. The dielectric study shows interesting behavior accompanied by structural transition. Our study suggests that Sm3+ doping plays an important role in governing the structural, luminescence, and dielectric properties of BiFeO3 samples.

With the advancement in research, new techniques are growing very fast these days. The environmental contamination by many hazardous elements is seen in today’s world. The radioactive materials and their byproducts or the leakage of nuclear reactors is a potential serious health threat. The ground water and drinking water get contaminated and it is a big challenge to remove these radioactive ions from the environment. The radioactive ions leach into groundwater and contaminate drinking water supplies for large population areas. The key issue in developing technologies for the removal of radioactive ions from the environment mainly from wastewater and their subsequent safe disposal is to devise materials which are able to absorb radioactive ions irreversibly, selectively, efficiently, and in large quantities from contaminated water. Hence, nanotechnology proved to be a great success in this area. Nanotechnology is the science and technology working at the molecular level i.e. in nanometre and embraces many different fields and specialties, including engineering, chemistry, electronics, medicine, pharmaceuticals, agriculture and waste management. The present chapter deals with the development of nano-technology for the removal and safe disposal of radioactive ions from the environment using nanomaterials.

Multidisciplinary research in chemistry, physics and other engineering sciences often addresses nanotechnology. In almost all branches of science and technology, nanotechnology is commonly used. Nanomaterials are not just something developed in the laboratory but nanotechnology has made it possible for humans to manufacture nanoform-containing materials. Metal nanoparticles have been used in different areas such as catalysis, sensor, and medicine. Nanoparticles have good efficiency, selectivity and yield of catalytic processes. Nanoparticles have higher selectivity in the reactions because the reactions continue with fewer impurities and less waste. Hence this technique is safer and more environmental-friendly. The specific emphasis of this chapter is on the applications of nanoparticles in organic synthesis.

The expanded interest in vitality assets, extraordinary endeavors, advocacy of convenient hardware and electric vehicles globally animates the improvement of energy storage gadgets, e.g., lithium-ion batteries and supercapacitors, toward higher energy density, which essentially relies on new materials utilized in these gadgets. Besides, energy storage materials assume a key part in productive, clean, and adaptable utilization of energy, and are vital for exploiting sustainable power systems. The usage of the thermal energy storage (TES) framework with phase change material (PCM) is a viable route for energy preservation and green-house gas emission reduction. Ongoing advances in atomically thin two-dimensional transition metal dichalcogenides (2DTMDs) have prompted an assortment of promising innovations for nanoelectronics, photonics, energy storage, and so on. Graphene and graphene-based materials have attracted extraordinary consideration due to their interesting properties of high mechanical adaptability, huge surface zone, chemical stability, prevalent electric and thermal conductivities that render them incredible as alternative electrode materials for electrochemical energy storage frameworks. The straightforward Chemical Vapour Deposition (CVD) and Atomic Layer Deposition (ALD) approaches offer another route for the creation of permeable materials for energy storage. Alteration of organic substrates with inorganic polyoxometalate (POM) clusters can be utilized to build nanocomposite materials with improved properties and various functionalities. Nanotechnology offers up new frontiers in materials research and construction to address the energy challenge by forming novel materials, particularly carbon nanoparticles, for efficient energy transformation and capacity, Polyaniline (PANi) as an auspicious material for energy storage/transformation, is merited for serious investigation and further progress. This book chapter discusses the various methods in materials for energy, their storage, and applications in numerous fields.

Dye sensitized solar cells (DSSCs) based on TiO2 nanoparticles film have attracted extensive attention from both industry and academia. Generally, the liquid electrolyte is used in dye sensitized solar cells, but the vaporization of liquid electrolyte hinders its commercialization as its affects its stability. And also the reduction in performance of dye sensitized solar cells was observed due to electron recombination in semiconductor liquid electrolyte interfaces. The situation worsens when the photoanode is in contact with the vaporization of electrolyte solution that affects the charge distribution at the semi conductor electrolyte interface and initiates photo corrosion on the photoanode. With the finding of ionic conductivity in polymer, electrolytes complexed with salt give a breakthrough to the development of DSSC devices. Various types of electrolytes have been developed and tested in different DSSCs configurations to overcome this problem. Among all polymer electrolytes, PEO (Polyethylene oxide) based polymer electrolyte has shown excellent performance in different electrochemical application areas. In DSSCs, it is also considered a novel candidate due to its excellent ability to form complexes with ionic salts. Poly(vinyl alcohol) (PVA) is also a promising candidate acting as a host polymer due to its inherent characteristics like high mechanical strength, good tensile strength, high temperature resistance, non toxicity, good optical properties and high hydrophilicity. PVA have a large extent of poly hydroxyl group, which makes PVA highly hydrophile. It also offers other advantages like excellent chemical stability, ease of preparation, and flexibility. In the present paper, we review different types of polymer electrolytes which have been used for improving the performance and stability of DSSCs.