Properties Of Glasses Research Articles

The effect of particle size on densification and mechanical properties of Fe-based bulk metallic glasses by spark plasma sintering

The effect of particle size on densification and mechanical properties of Fe-based bulk metallic glasses by spark plasma sintering

Various rejuvenation behavior of Cu–Zr–Al-(Sn) metallic glass via deep cryogenic cycling treatment

Deep cryogenic cycling treatment (DCT) has been used to rejuvenate Cu–Zr–Al-(Sn) bulk metallic glasses (BMGs). The thermally treated samples exhibit rejuvenated behaviors characterized by improved enthalpy of relaxation and plasticity. Notably, the degree of rejuvenation varies significantly in Sn-doped samples compared to the Sn-free counterparts. Molecular dynamics simulations reveal that Sn doping leads to a decrease in the peak height of Cu–Zr atom pairs and a significant increase in Zr–Zr atom pairs. The negative mixing heat between Sn and Zr results in the degradation of short-range ordered structures between Cu–Zr, generating the clusters with more Zr atoms and a subsequently more closely packed structure. Such structural modification is associated with the less obvious rejuvenation in Sn-doped samples. Furthermore, the addition of Sn reduces the fraction of polyhedral structures with higher five-fold symmetry, particularly <0, 0, 12, 0>, thereby negatively impacting the rejuvenation behavior during DCT. The changes in microstructure during rejuvenation also influences the shear localization under external shear deformation. The reduction in the proportion of polyhedra with relatively higher five-fold symmetry, such as <0, 0, 12, 0>, leads to a more pronounced activation in local regions. These activated local shear units contribute to the delocalization of shear flow and the initiation of additional shear bands. The present study sheds light on the intricate interplay between Sn doping, microstructural changes, and the resulting mechanical properties in metallic glasses subjected to deep cryogenic cycling.

Physical, optical, thermal, structural and mechanical properties of alkaline earth borate glasses

Binary alkaline earth borate glasses were synthesized via the melt quenching technique. The density and molar volume of the resultant glasses were determined experimentally. The glass optical basicity has been found to increase with the glass polarizability. The optical properties of the glasses were comprehensively analyzed, revealing a shift in the cutoff wavelength towards longer wavelengths with increasing glass optical basicity. Additionally, the optical band gap (Eg) was estimated. Structural investigations unveiled an increase in the abundance of BO4 units as the glass optical basicity increased. Furthermore, the glass transition temperature was observed to decrease with decreasing cation field strength. Glass packing density and B2O3 packing factor were calculated to assess structural variations. The longitudinal and shear velocities were determined using the pulse echo technique, providing insights into the elastic moduli of the glasses. The Makishima and Mackenzie approach was employed to predict the elastic moduli, yielding results in good agreement with experimental data. This comprehensive analysis sheds light on the relationship between composition, structure, and mechanical properties of binary alkaline earth borate glasses, offering valuable insights for potential applications.

Influence of sodium oxide substitution on structural and gamma-ray radiation shielding properties of sodium borosilicate glass

In this paper, borosilicate glasses with varying concentrations of sodium oxide were synthesized using the melt-quenching method. The amorphous nature of the glasses under investigation, with a composition of (20 + x)Na2O-(60-x)B2O3–20SiO2 (where x = 0, 3, 5, 7, 8, 10, 13, 15, 17, and 20 mol%), was confirmed through X-ray diffraction (XRD) analysis. Fourier-transform infrared (FT-IR) spectroscopy was employed to analyze the glasses and revealed an increase in the concentration of non-bridging oxygen atoms (NBO) with increasing amounts of Na2O. The N4 parameter, which represents the fraction of NBOs, was calculated and found to decrease from 74% to 52% as the concentration of Na2O increased. The density of the glasses increased from 2.391 g/cm3 to 2.744 g/cm3 when B2O3 was replaced with Na2O, while the molar volume decreased from 27.68 cm3/mol to 23.56 cm3/mol. Theoretically, theoretical calculations were performed using newly developed computer software called Phys-PSD to assess their shielding properties, including attenuation coefficients, half value layer, and buildup factors. The calculations were conducted in the energy range of 0.015–15 MeV. The results indicated that the synthesized glasses exhibited promising potential as radiation shields.

Effect of Crystallization on Local Structure and Optical Properties of Glass with 12.5Li2O–50GeO2–37.5P2O5 Composition

Effect of Crystallization on Local Structure and Optical Properties of Glass with 12.5Li2O–50GeO2–37.5P2O5 Composition

Numerical approximation for the radiation shielding properties of borosilicate glasses with ZnO using piecewise cubic Hermite interpolating polynomials and Akima interpolation

Numerical approximation for the radiation shielding properties of borosilicate glasses with ZnO using piecewise cubic Hermite interpolating polynomials and Akima interpolation

Enhanced mechanical and thermophysical properties of Mg2Ca, Al2Ca, and Al4Ca bulk metallic glasses in comparison to crystalline alloys for bone grafting applications: A molecular dynamics investigation

We investigate the glassy-state properties of Mg2Ca, Al2Ca, and Al4Ca from the grafting application viewpoint. We employed classical molecular dynamics to examine the phase transition, structural, thermodynamic, transport, and mechanical properties in the amorphous state. All properties suggest successful simulations of the glass phase at and below the glass transition temperature, ranging between 550 and 689 K for Mg2Ca, Al2Ca, and Al4Ca. Computed results are compared and discussed with the reported findings and known mechanical and thermal properties of the various parts of the human bones and biocomposites. The comparison establishes that the mechanical, thermal, and transport properties significantly improve in the glass phase compared to its crystalline alloy form. At 300 K, studied glasses have densities in close agreement with human bone density. Structural analysis and heat capacity show the second-order phase transition, verifying the formation of the glass structure. The targeted glasses exhibit excellent thermal conductivity and thermal diffusivity compared to other commonly used biocomposites for bone grafting. Furthermore, the simulated elastic properties, viz., the Poisson ratio, G/B ratio, Cauchy's pressure, and yield strength, are in close agreement with the mechanical properties of various parts of human bone. The predicted ductility nature, contrary to the brittle character of Mg2Ca, Al2Ca, and Al4Ca crystalline alloys, proves the superiority of the glassy form for the implant's functioning. The minimum enthalpy of formation and thermodynamic stability of studied compounds benefit the synthesis process; hence, we propose that the studied glasses are persuasive materials for experimental synthesis aimed at bone grating applications.

Abnormal endothermic liquid–liquid phase transition upon cooling Pd40Ni40P20 melts

Liquid–liquid phase transition (LLPT) is the transformation of a liquid from one distinctive structure to another with the same composition. However, the origin of the structural variation at LLPT is still controversial. Here, we used ab initio molecular dynamics simulation to verify and investigate a high-temperature LLPT in a Pd40Ni40P20 melt; this melt showed a reduction in the nuclei interference of the conventional low-temperature LLPT. An abnormal endothermic LLPT was confirmed with flash differential scanning calorimetry, indicating a change in the atomic short-range-order structure around the P–P bond and a decrease in the number of specific icosahedral-like clusters, such as ⟨0 2 8 0⟩ and ⟨0 2 8 1⟩. The structural change of the P-centered clusters changed the solidification path through potential energy adjustments. Our results showed the structural mechanism of the unusual endothermic phenomenon and provided a different insight into regulating the properties of metallic glasses.

Exploring structural and optical properties of Cu-doped and Fe-doped sodium borate glasses

This study investigated the structural and optical properties of Cu-doped and Fe-doped sodium borate glasses. X-ray diffraction (XRD) patterns confirmed that both samples were amorphous, with no sharp peaks. However, differences in the width and center of the high-intensity humps suggested variations in atomic packing and field strength between the two samples. Fourier transform infrared (FTIR) spectra showed wider vibrational modes and stronger absorption in the Fe-doped sample, confirming its higher atomic packing and field strength. Luminescence spectra indicated that the Cu-doped sample had a higher ratio of Cu2+:Cu3+ than the Fe-doped sample of Fe2+:Fe3+, resulting in greater UV–visible region absorption. Optical parameters such as absorbance, transmittance, and reflectance supported these findings, with the Fe-doped sample exhibiting higher absorbance band edges. Quality factor (Q.F.) analysis revealed that the Fe-doped sample had a larger Q.F. than the Cu-doped sample, indicating lower energy losses. Furthermore, the optical conductivity of both samples increased with photon energy, with the Cu-doped sample dominating in all energy regions. Finally, both samples exhibited high effective atomic numbers, suggesting potential applications in radiation shielding, with the Cu-doped sample having a wider radiation shielding window. Finally, the findings unique structural and optical properties suggests the Cu-doped and Fe-doped sodium borate glasses to a lot of potential applications in various fields including radiation shielding, optics, electronics, and energy storage.

Synergistic optimization of physical, thermal, structural, mechanical, optical and radiation shielding characteristics in borate glasses doped with Bi2O3

This paper presents the effect of Bi2O3 on physical, thermal, structural, mechanical, optical, and radiation shielding properties of borate-based glasses having a composition (60-x)B2O3–25Na2O–13BaO-2Gd2O3-xBi2O3; x = 0, 5, 10, 15, and 20 mol%. XRD analysis confirms the amorphous structure of the prepared glasses. As Bi2O3 content increases from 0 to 20 mol%, density of the glasses increases from 2.729 to 3.896 g/cm3, and molar volume rises from 30.947 to 42.017 cm3/mol. The glass transition temperature (Tg) of the samples decreased with Bi2O3 content. FTIR analysis reveals the presence of BO3, BO4, BiO3, and BiO6 structural units in the prepared glasses. Optical absorption studies indicate a decrease in band gap energy from 3.006 to 2.573 eV for indirect transitions implying non-bridging oxygen atom formation and this inference is supported by both physical and FTIR results. The elastic parameters, derived from Makishima-Mackenzie model decreased with increased Bi2O3 concentration suggesting a reduction in mechanical properties. The mass attenuation coefficient (μm), determined through experimental measurements and using Phy-X/PSD software, yielded closely aligned values. Other shielding parameters such as half-value layer (HVL), mean free path (MFP), and effective atomic number (Zeff) were also calculated. The glass containing 20 mol% Bi2O3 exhibited a significant gamma-ray shielding potential due to its high μm value, (0.1260 cm2/g at 0.511 MeV and 0.0960 cm2/g at 0.662 MeV) and Zeff together with low HVL and MFP. A Comparative analysis of the μm values for the present glasses and that of other glasses containing Bi2O3 is also presented.

On the structure and icosahedral interconnectivity in Tantalum monatomic glass produced under pressure

Proper processing of bulk metallic glasses (BMGs) under pressure is a promising approach to tailor their properties. However, to fully understand how pressure processing affect the final glass properties, a clearer understanding of how the pressure affects the structure of the glass at both short- and medium range levels is required. Accordingly, using molecular dynamics simulations, we study the effect of cooling under pressure on the local structure and the medium-range connectivity in a model Tantalum monatomic metallic glass. Crystalline grains form in the Ta sample with increasing the pressure under which the sample was cooled. These observations were confirmed by decreasing the fivefold symmetry with increasing pressure. The connectivity type between the perfect icosahedra was determined and showed that when cooled under pressure, intercross sharing is favored in the higher pressure. This work gives insights into understanding local structural changes induced by the pressure in metallic glasses.

BaTiO3-B2O3-MgO-Na2O-CaO glass series: Radiation shielding, thermal, and mechanical properties

The effect of BaTiO3 on the mechanical, thermal and radiation shielding properties of the borate glass with the composition of (60-x)B2O3 + 10MgO + 15Na2O + 15CaO+(x)BaTiO3 (x: 0,2.5,5,7.5 and 10 mol%) were synthesized by the melt quenching method. The physical, thermal, mechanical and radiation protection properties of the glasses produced with this designed composition were carefully investigated. As the BaTiO3 amount increased from 0 % to 10 %, the density of the glass increased from 2.571 to 2.870 g/cm3 and the glass thermal stability (ΔT) also enhanced from 51 to 63. The LAC value at 276 keV, 0.2831 cm−1 for 0 % BaTiO3 and enhanced linearly with increasing BaTiO3 concentration and reach to 0.3475 cm−1 at 10 % BaTiO3. The experimentally obtained MAC values are in agreement with the theoretically calculated MAC values with XCOM and MCNP6.2. It was concluded that the increase in the BaTiO3 value of the glass positively affects the radiation shielding properties of the glasses.

Effect of lanthanum oxide on the radiation-shielding, dielectric, and physical properties of lithium zinc phosphate glasses

This study looked at the shielding properties, physical properties, and dielectric spectroscopy of various lanthanum oxide concentrations based on (65-x) P2O5-15 Li2O–15ZnO– 5Bi2O3- xLa2O3 with x = 0.0, 1.0, 2.0, 3.0, and 4.0 mol% glasses. When La2O3 is added, the molar volume quantities fall but the density values increase. The sample with the designation La-4.0 (4.0 mol% La2O3 content) had the highest density observed, 3.2182 g/cm3. Monte Carlo simulations and the Phy-x/PSD software were used to determine the critical gamma radiation attenuation characteristics, particularly linear attenuation coefficients and mass attenuation coefficients of glass samples under investigation. The half-value layer, mean free path, effective atomic number and effective electron density were then examined across a wide energy range (0.015–15 MeV). The findings of the investigation showed that the addition of La2O3 decreased the half-value layer and mean free path while increasing the mass attenuation coefficient, effective atomic number, and effective electron density. The results indicate that the inclusion of La2O3 appears to improve that glass system's ability to deflect gamma and neutron radiation. Over a broad frequency range, the dielectric properties were measured. The dielectric constant (ε′), which is typically steadily decreased with the addition of lanthanum, indicates an increase in the degree of electrical stiffness inside the glass network. Among the samples examined, the glass sample La-4.0 is thought to possess the best properties for electronic packaging due to its maximum propagation speed and lowest dielectric constant.

Probing of CoO-induced nano-sized defects in Li2SO4–MgO–P2O5 glasses: Insights from positron annihilation lifetime spectroscopy

This study investigates the influence of CoO doping on concentration and characteristics of nano-sized cavities in Li₂SO₄-MgO-P₂O₅ glasses using positron annihilation lifetime spectroscopy (PALS). These defects are known to significantly impact the physical properties of glasses. Glasses with compositions of 20 Li₂SO₄-20MgO-(60-x) P₂O₅: x CoO (0 ≤ x ≤ 1.0 mol%), were prepared using melt-quench technique. PALS analysis revealed a strong dependence of positronium (e⁺- e⁻ pair) lifetime on CoO concentration. The analysis of the results further indicated that the fraction of free volume Δf/f0) and cavity radius (R) reached minimum values between 0.6 and 0.8 mol% CoO, but increased with further CoO doping. This suggests that cobalt ions prefer Oh sites, act as network modifiers, and create a larger concentration of free volume defects when CoO is increased beyond 0.8 mol%. Notably, the PALS-derived free volume defect concentration with CoO concentration is found to follow nearly same trend exhibited by the results of optical absorption and AC conductivity studies.

The role of WO3 on the optical and radiation attenuation characteristics of ZnO–Na2O–B2O3 glasses

This works aims to investigate the role of the WO3 on the optical and radiation attenuation characteristics of ZnO–Na2O–B2O3 glasses which were called as ZNBW glasses using theoretical approach. The molar refractivity (Rmol), molar polarizability (αMol.), reflection loss (RLoss), static dielectric constant (εstatic), and optical dielectric constant (εoptical) of the ZNBW glasses enhance while optical transmission (TOpt.) and metallization criterion (M) of the ZNBW glasses reduce with enhancement of WO3 and decreasing of ZnO. The Rmol, αMol.,RLoss, εstatic and εoptical are the highest for ZNBW20 whereas they are the lowest for ZNBW0. The TOpt. and M are the highest for ZNBW0 while they are the smallest for ZNBW20. In terms of radiation attenuation characteristics, the linear attenuation coefficient, mass attenuation coefficient, effective atomic number, and effective electron density increase whereas half value layer, tenth value layer, mean free path and fast neutron removal cross section (FNRC) decline with the enhancement of WO3 and reducing of ZnO. The ZNBW20 which has the highest WO3 content possesses the greatest radiation attenuation properties and smallest FNRC whereas the ZNBW0 which has not WO3 content possesses the smallest radiation attenuation properties and the highest FNRC. Consequently, radiation attenuation characteristics of ZNBW glasses enhance whereas FNRC of ZNBW glasses decline with addition of WO3 and reducing of ZnO. The replacement of WO3 by ZnO has a positive effect on improving the radiation attenuation properties of the ZNBW glasses.

Prediction of optical properties of rare-earth doped phosphate glasses using gene expression programming

The progression of optical materials and their associated applications necessitates a profound comprehension of their optical characteristics, with the Judd–Ofelt (JO) theory commonly employed for this purpose. However, the computation of JO parameters (Ω2, Ω4, Ω6) entails wide experimental and theoretical endeavors, rendering traditional calculations often impractical. To address these challenges, the correlations between JO parameters and the bulk matrix composition within a series of Rare-Earth ions doped sulfophosphate glass systems were explored in this research. In this regard, a novel soft computing technique named genetic expression programming (GEP) was employed to derive formulations for JO parameters and bulk matrix composition. The predictor variables integrated into the formulations consist of JO parameters. This investigation demonstrates the potential of GEP as a practical tool for defining functions and classifying important factors to predict JO parameters. Thus, precise characterization of such materials becomes crucial with minimal or no reliance on experimental work.

Modeling optimization design and amplification characteristics of O-band irregular Bragg bismuth-doped fiber amplifier

In recent years, O-band bismuth-doped fiber amplifier (BDFA) have been rapidly developed due to the fluorescence properties of bismuth-doped glass in the near-infrared (NIR) band, while there are still few studies on bismuth-doped fibers (BDF) with large mode fields as of now. In addition, although the use of a double-pass structure on the amplifier can lead to gain improvement, this also deteriorates the noise figure (NF). Therefore, the study of bismuth-doped fibers with large mode-field areas is a promising path to develop high-performance BDFA. In this work, taking a commercial bismuth-doped fiber as an instance, we first measured the refractive index distribution of the BDF in the O-band using a self-developed fiber refractive index tester, and thereby obtained its actual mode-field area. Then, based on this we further propose an irregular Bragg bismuth-doped fiber with the refractive index growing layer by layer. The results suggests that the effective mode-field area of this fiber reaches 401 um2 at 1320 nm, which is nearly 5.8 times that of a common single-mode BDF. Finally, we performed numerical simulations of the amplification performance based on this fiber. Under the condition of total pumping power of 8 W, the signal with −20 dBm input power obtains a gain of more than 54 dB and an NF of less than 5 dB at 1320 nm wavelength. This work demonstrates the great potential of this Bragg bismuth-doped fiber as an O-band high-gain amplifier and high-power laser.

Photon shielding properties of oxyfluoride aluminophosphate glass added with Sb2O3 by using PHITS Monte Carlo simulation and experimental methods

The glass formula (65-x)P2O5–5CaF2–10NaF–10KF–10AlF3-xSb2O3 (x = 0, 5, 10, 15 mol%) were produced by melt quenching technique for photon shielding application. The present glasses were investigated for the physical, structural, optical, gamma ray and x-ray shielding properties. The results revealed that the density increased when concentrations of Sb2O3 increased, the Fourier Transform Infrared (FTIR) and the X-ray diffraction (XRD) results illustrated the functional groups of vibrations, and confirmed the amorphous behavior, respectively. The transmission spectra of present glasses showed higher transparency than x-ray windows. The comparative studies of gamma-ray between experiment and theoretical, the mass attenuation coefficients (MAC), effective atomic number (Zeff), and effective electron density (Neff) were increased with increasing concentration of Sb2O3. On the other hand, the half value layer (HVL) was decreased. The energy absorption buildup factor (EABF) and exposure buildup factor (EBF) of dopant Sb2O3 in present glass were calculated and discussed in terms of energy and concentration of Sb2O3. As a result of using the X-ray source, the HVL was decreased with a rise in Sb2O3 contents. HVL value at 15 mol% of Sb2O3 concentration is higher than the standard materials at 120 kVp. The Sb2O3 glass systems can be a candidate for radiation shielding material.

Enhancing bioactivity, radiopacity, and structural properties of borophosphate glass through barium oxide modification and controlled thermal treatment

This study explores the impact of replacing P2O5 and B2O3 with varying amounts of barium oxide (BaO, 0–10 mol%) in borophosphate glasses. The investigation focuses on the structural, bioactivity, and radiopaque properties of the resulting materials. Four glass samples were prepared using a melt-quench technique. Their bioactivity was assessed through immersion in simulated body fluid (SBF) for 28 days. Additionally, a 24-h thermal treatment at 530 °C was employed to induce crystallization and evaluate the bioactivity of the resulting glass-ceramics. Initial X-ray diffraction (XRD) analysis confirmed the amorphous nature of the glasses. Conversely, crystalline phases were identified after the thermal treatment. Increasing BaO content led to higher volumetric density while altering the molar volume and structure as revealed by Fourier-transform infrared spectroscopy (FTIR) analysis. Lower pH values were observed with increasing BaO content, suggesting its influence on controlling the release of ions from the material. Both XRD and FTIR analyses detected the formation of hydroxyapatite (HAp) and fluorapatite (FAp) phases in all samples. Notably, the glass-ceramic containing 10 mol% BaO exhibited the most significant apatite formation. Radiopacity measurements improved with increasing BaO content, indicating potential applications in bone replacement materials due to enhanced visibility in X-ray imaging. Cell viability tests confirmed the non-toxic nature of the samples, with higher BaO content promoting cell proliferation, suggesting potential for tissue regeneration. Overall, these findings suggest promising biomedical applications for all the studied compositions.

Effect of Intrinsic Defects on the Structural and Optical Properties of Borosilicate Glasses Containing Rare-Earth Ions

Effect of Intrinsic Defects on the Structural and Optical Properties of Borosilicate Glasses Containing Rare-Earth Ions