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The present report is an investigation of morphological, structural and magnetic properties of multicomponent glass-ceramics with respect to content of nucleating agent (TiO2) as well as thermal processing parameters. Structural features of these glass-ceramics were explored by their crystalline phase analysis and morphological studies after sintering at various temperatures (850–1000 °C) for 2 h (h). The samples exhibited near superparamagnetic nature which would be helpful for heat generation purposes (such as in hyperthermia treatment of cancer). Magnetic properties of the glass-ceramics are dependent on the crystallized phases grown upon sintering. Concentration dependent role of TiO2 is discussed based upon the obtained results.

Glasses with compositions SiO 2 -CaO-Al 2 O 3 -TiO 2 -Na 2 O were prepared by conventional melt quench technique. The dielectric properties of these glasses with a variation in alkali content over a frequency range from 20 Hz to 1 MHz and temperature variation of 30–280 °C have been investigated. The electric modulus representation has been used to provide comparative analysis of the ion transport properties in these glasses. The conductivity isotherms show a transition from frequency independent dc region to dispersive region where the conductivity continuously increases with increasing frequency. The present glasses exhibit conductivity in the range of 10 − 5 to 10 − 3 S/m which is higher than the alkali containing silicate glasses. Hysteresis loop observed at room temperature confirms the ferroelectric nature of glasses.

Composition of (40-x)SrO-(x)BaO-45SiO2-10B2O3-5ZrO2 (x=0,10,20,30 and 40 mol%) are synthesized by melt quench technique. The as prepared samples are characterized using various experimental techniques to study their structural, optical (insulating) and thermal expansion coefficient (TEC) to check their suitability as glass sealants. Alkaline earth mixed modifier effect is observed on all the properties. However, it is more pronounced when SrO/BaO modifiers ratio is approached to 1 in the present glasses. All glasses exhibit optical band gap in moderate insulating range viz. 3.2-3.8eV. TEC of as prepared glasses is also in required range of SOFC sealants except glass having x=20 mol% (SB-20). Softening temperature of all the glasses is higher than 700°C except this glass. Based on present study, glass having x=10 mol% (SB-10) could be suitable as a sealant for intermediate temperature (600-800°C) solid oxide fuel cell.

Glasses B2O3-Li2O-ZnO-V2O5 are investigated for their structural, thermal properties and non-isothermal crystallization kinetics. ZnO is systematically replaced with V2O5 in order to get insight on structural and thermal behavior of the glasses. Differential thermal analysis (DTA) curves of glasses are obtained at various heating rates. The characteristic temperatures obtained from DTA are used as inputs for various mathematical models to calculate activation energies for various thermodynamic processes and thermal parameters such as Avrami's constant, thermal stability, and fragility index. The obtained results are correlated to extract valuable information on the crystallization behavior of the glasses and also the structural role played by the transition metal oxides in the present oxide glasses. V2O5 increased the bulk crystallization and acted as modifier in the present glasses. The results are expected to help designing glasses and specifying their operating temperature ranges for probable applications in photonics and as cathode materials in electronics.

Glasses of composition 55P 2 O 5 –(45- x )Na 2 O– x K 2 O; (5 ≤ x ≤ 25) have been prepared by melt-quench technique. The broad halo in all quenched samples indicates their amorphous nature as confirmed by X-ray powder diffraction. The mixed glass modifiers effect (MGME) on crystallization and thermal stability are investigated using the differential thermal analyzer under non-isothermal conditions. The kinetic of crystallization has been studied using Kissinger's and Augis–Bennett models. The activation energies for glass transition ( E g ) and crystallization ( E c ) are observed maximum for 10 and 20 mol% K 2 O glasses. 10 and 20 mol% K 2 O contained glasses exhibit minimum crystallization frequency than other glasses, which indicate their higher kinetic and thermodynamic stability. FTIR and Raman analysis confirmed the higher polymerization of phosphate groups in 10 and 20 mol% K 2 O glasses as compared to other glasses.

The structural and optical properties have been investigated for the 30Li2O–55B2O3–5ZnO–xTiO2–(10 − x)V2O5, (0 ≤ x ≤ 10) glasses using different spectroscopic characterization techniques. The relationship between optical and structural properties has been established in light of the variation of TiO2 content. The band gap shows a decreasing trend with a decrease in V2O5 content. Physical parameters like density, molar volume, ionic concentration and inter ionic distance have been obtained for all the glass compositions. Theoretical parameters like optical basicity, oxide polarizability and electronegativity have been obtained and discussed in relation to the non-bridging oxygen (NBO). Bulk modulus has been calculated theoretically and correlated with average stretching force constant and network bonds/volume.

Glasses and glass ceramics with composition of 45SiO2–25CaO–5P2O5–10Na2O–(15 − x)MnO2 − xFe2O3(x = 0, 5, 10 and 15) were prepared by melt-quenching technique. In the present work, the physical, structural and optical properties of these samples were investigated and correlated with the structural changes induced in the samples due to replacement of MnO2 with Fe2O3. Density and molar volume of the samples increased with Fe2O3 addition. Fe3 + is reduced to Fe2 + due to depleted presence of oxygen at 1550 °C in furnace and formed in-situ nano-crystalline phase in x = 10 and 15 samples, which enhanced the optical and structural stability of the samples. High Fe2O3 content prevented glass formation as observed in XRD results. The optical band gap decreases and sharpness of FTIR bands increases with Fe2O3 content. Highest refractive index and lowest Fermi energy is obtained for x = 15 sample.

In the present study, xNa 2 S + (100 − x)P 2 S 5 35 ≤ x ≤ 60 glasses and glass ceramics have been prepared by melt quenching technique. The glasses and glass ceramics have been characterized using XRD, Raman and FT-IR spectroscopy. All glass samples show phase separation. For x = 60, two crystalline phases Na 3 PSO 3 and Na 4 P 2 O 7 are observed. The H 2 S generation and stability of Na 2 S–P 2 S 5 glasses after exposure to air at different time intervals are investigated using gas chromatography. The amount of H 2 S generated from Na 2 S–P 2 S 5 glasses exposed to air is found to be dependent on the glass compositions. Raman spectroscopy demonstrates that the 45Na 2 S–55P 2 S 5 and 55Na 2 S–45P 2 S 5 (mol %) glasses exhibit minor structural changes as compared to other compositions.

An attempt has been made to understand the role of modifiers on physical, mechanical and spectroscopic properties of AO-SiO 2 –B 2 O 3 -La 2 O 3, (A = Mg, Ca, Sr, Ba) glasses. The replacement of alkaline earth metals which act as modifier in glass matrix exhibit, marked difference in their strength and optical properties. The results are discussed in light of non-bridging oxygens (NBO), optical basicity, refractive index, polarisability, hardness and fracture toughness. In addition to this, Weibull statistics and cumulative probability of failure have also been analyzed. Band gap of glasses has been calculated using UV–visible spectroscopy where the variation in band gap is observed to increase with the addition of heavier modifier. Raman features have been explored for all prepared samples through Raman spectra which is in agreement with Fourier transform infra-red (FTIR) spectroscopy and Fourier transform nuclear magnetic resonance (FT-NMR).

SiO 2 –BaO–ZnO–xB 2 O 3 –(10−x) Y 2 O 3 , (0 ≤ x ≤ 10) glasses are synthesized. The effect of Y 2 O 3 on the structural and optical properties of glasses has been investigated using different characterization techniques. The results are discussed in light of non-bridging oxygens (NBO), optical basicity and heat-treatment of glasses. The band gap has been calculated for as cast and heat-treated glasses. The band gap energy is found to decrease with the increasing content of Y 2 O 3 in the glasses and heat-treatment. The presence of the crystalline phase in the glass matrix showed remarkable effect on band gap which decreases to semiconducting range.

Glass of composition 40SiO2–30BaO–20ZnO–10B2O3 (mol%) was made by conventional melting and casting process. Crystallization kinetics of above glass has been investigated under non-isothermal conditions, using the formal theory of transformations for heterogeneous nucleation. The procedure is applied to the experimental data obtained by differential thermal analysis (DTA), using continuous-heating techniques. The crystallization results are analyzed, and both the activation energy of crystallization process as well as the crystallization mechanism is characterized. Dilatometric measurement of this glass was also done and data obtained was used to calculate the viscosity of the formed glass. Development of crystalline phases on thermal treatments of the glass at various temperatures has been analyzed by X-ray diffraction. Microstructure of the crystalline phases was investigated by scanning electron microscopy (SEM) and the development of various structural features with variation in heat treatment cycle was observed. The nucleation and growth of these phases in the matrix of glass has been described and discussed.