Nano-mechanical, optical and structural property correlations in binary, ternary, and quaternary tellurium-based chalcogenide glasses
Over a half century, from the advent of chalcogenide glasses, it was used for various applications like xerography, phase change memories (PCM), solar cells, infrared devices and so on. These applications made use of some interesting properties exhibited by these glasses like photoconductivity, amorphous to crystalline transition, photovoltaic effect, refractive index changes, and so forth. Development of newer chalcogenide systems in the past two decades paved the way for their promising future in PCMs, where the significant difference in properties (optical, electrical, thermal) between amorphous and crystalline state lead to efficient information storage. Systematic studies on different properties exhibited and their optimization help in successful development of chalcogenide glasses for various device applications. In this thesis work, Multicomponent chalcogenide glasses (binary, ternary and quaternary) are compared for their mechanical and optical properties, homogenization studies in quaternary chalcogenide glasses and its effects are studied in detail. Efforts are also made to understand the effect of rigidity and intermediate phase on the composition dependence of properties investigated in Ge15Te68In5Ag12 glasses. This thesis consists of 5 chapters; a brief summary is given below. Chapter 1 provides a brief overview of the Chalcogenide glasses, their applications, local structures and the scope of the present work. Chapter 2 discusses the effect doping in binary, ternary and quaternary Te based centroid compositions. Their optical, structural, and mechanical properties had been investigated and results were reported. Chapter 3 investigates the effect of homogenization on centroid glass compositions of quaternary Ag based chalcogenide system. The samples were kept in furnace for different time duration and their structural, thermal, optical and mechanical properties were investigated and reported. Chapter 4 shows the detailed study of the optical and mechanical behavior of completer glass forming region in Ag based quaternary chalcogenide glass systems. The study also investigates dynamic viscoelastic behavior of these glasses in different phases (Floppy, IP and Rigid) Finally, Finally, the results and observations of all the studies are summarized in Chapter 5.