High niobium oxide content in germanate glasses: Thermal,structural, and optical properties

Niobium alkali germanate glasses were synthesized by the melt‐quenching technique. The ternary system (90‐x)GeO₂–xNb₂O₅–10K₂O forms homogeneous glasses with x ranging from 0 to 20 mol%. Samples were investigated by DSC and XRD analysis, FTIR and Raman spectroscopy, and optical absorption. Structural and physical features are discussed in terms of Nb₂O₅ content. The niobium content increase in the glass network strongly modifies the thermal, structural and optical properties of alkali germanate glasses. DSC, Raman and FTIR analysis suggest niobium addition promotes NbO₆ groups insertion close to GeO₄ units of the glass network. XRD analysis also pointed out that samples containing high niobium oxide contents exhibit preferential niobium oxide‐rich phase after crystallization after heat treatment, which is similar to orthorhombic Nb₂O₅. Absorption spectra revealed high transmission range between 400 nm to 6.2 μm, added to a considerably decreased hydroxyl group content as the addition of niobium in the alkali germanate network. The niobium oxide‐rich phase crystallization process was studied and activation energy was determined, as well as nucleation and crystal growth temperatures and time for obtaining transparent glass‐ceramics.     

Structural and Optical Properties of Erbium and Ytterbium Codoped Germanoniobophosphate Glasses

A series of glasses with compositions of 20Na₂O–30Nb₂O₅–(5?y?z)Al₂O₃–30P₂O₅–(15?x)TiO₂–xGeO₂–yEr₂O₃–zYb₂O₃, where x = (0; 5; 10; 15), y = (0; 1), z = (0; 2) mol%, were investigated with respect to their structural, optical, and luminescence properties. The coordination of the germanium(IV) ion is normally reported as being mainly tetrahedral. However, results of this study suggest that the germanium(IV) ion may have an octahedral coordination and that TiO₂ is substituted. This proposition can be done mainly by ³¹P MAS‐NMR spectroscopy, which spectra show predominantly pyrophosphate chains in the different glasses, without changes in their polymerization after substitution. A similar coordination of germanium can also be identified by the photoluminescence behavior of the different codoped samples, which shows similar erbium(III) emission decay lifetimes (5 ms), and Judd–Ofelt intensity parameters. It was found that the upconversion emission process involved 1.5 photons. Regarding the thermal behavior, it is noted that the glasses containing higher proportions of GeO₂ exhibit higher thermal stability and are therefore more resistant to devitrification when compared to compositions containing more TiO₂.     

Effect of Ta2O5 Substituting on Thermal and Optical Properties of High Refractive Index La2O3–Nb2O5 Glass System Prepared by Aerodynamic Levitation Method

High refractive index glasses with nominal composition of 0.35La₂O₃–(0.65?x)Nb₂O₅–xTa₂O₅ (x ≤ 0.35) were prepared by aerodynamic levitation method. The effect of Ta₂O₅ substituting on their thermal and optical properties was investigated. All the glasses obtained were colorless and transparent. Differential thermal analyzer results show that as the content of Ta₂O₅ increased, the thermal stability of the glasses increased but the glass‐forming ability decreased. The transmittance spectra of all the obtained glasses exhibited a wide transmittance window ranging from 380 to 5500 nm. As the content of Ta₂O₅ increased, the refractive index of the glasses was enhanced from 2.15 to 2.21 and the dispersion was reduced with the Abbe number increasing from 20 to 27.     

Effect of the Glass Structure on Emission of Rare‐Earth‐Doped Borate Glasses

A series of glasses composed of xB₂O₃–8Al₂O₃‐(90?x)Na₂O–R₂O₃ (x = 65, 70, 75, 80, 85; R = Dy³⁺, Tb³⁺, Sm³⁺) were prepared through melt‐quenching. Structural evolution was induced by varying the glass composition. Increasing the glass network former B₂O₃ enhanced the luminescence of rare‐earth ions, as observed in the emission spectra. The mechanism of the glass structural evolution was investigated by the NMR spectra analysis. The dispersant effect of the glass structure was believed to promote the better distribution of the rare‐earth ions in the matrix and reduced the concentration quenching between them. The relationship between the glass structure and its optical properties was established.     

Transparent glass and glass-ceramic in the binary system NaPO3-Ta2O5

Transparent and homogeneous tantalum phosphate glasses were prepared in the binary system (100-x)NaPO₃-xTa₂O₅ with x varying from 10 to 50 mol%. Thermal, structural, and optical properties, as well as crystallization mechanisms, were investigated by thermal analysis, X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopies, optical absorption, transmission electron microscopy in terms of Ta₂O₅ content. FTIR and Raman results support the tantalum insertion in the phosphate chains with [TaO₆] polyhedra cross-linking the phosphate units. At higher Ta₂O₅ content, [TaO₆] clusters are formed and connected to the phosphate network by P-O-Ta bonds. This structural evolution is in good agreement with the thermal features measured by differential scanning calorimetry (DSC) with a strong increase of the T_g temperatures up to 920°C, high thermal stability against crystallization for low Ta₂O₅ content and increasing of crystallization tendency for the most Ta-concentrated samples. Besides, due to the progressive insertion of [TaO₆] units, the precipitation of Na₂Ta₈O₂₁ perovskite-like phase was identified in the sample with 50 mol% of Ta₂O₅. The optimal heat treatment conditions were identified using DSC measurements and a transparent glass-ceramic from 50NaPO₃ to 50Ta₂O₅ composition was prepared. The obtaines glass-ceramic has great potential for optical applications, such as host for rare-earth ions, nonlinear optical materials, and ferroelectric domain.     

Quantitative prediction of the structure and properties of Li2O–Ta2O5–SiO2 glasses via phase diagram approach

Tantalum silicate glasses serve as laser host materials to take advantage of their high refractive index and the ability to tailor their physical properties in the design of high-performance photonic and photoelectric components. However, successful attainment of feature control in tantalum-doped materials remains a longstanding problem due to the limited understanding of local structure around the tantalum ions, a problem that lies at the heart of predicting the micro- and macroscopic properties of these glasses. Herein, we present a novel approach for predicting the local structural environments in tantalum silicate glass based on a phase diagram approach. The phase relations and glass formation region of Li₂O–Ta₂O₅–SiO₂ ternary systems are explored to calculate the structure and additive physical properties of lithium tantalum silicate glasses. These measured and calculated results are in good quantitative agreement, indicating that the phase diagram approach can be applied broadly to Li₂O–Ta₂O₅–SiO₂ ternary glass systems. Using the phase diagram approach, the local structure of tantalum can be directly obtained. Each Ta atom is surrounded by six atoms, and its polyhedron, the TaO₆ octahedron, bonds through oxygen to Li and Ta. As a network modifier, Ta⁵⁺ depolymerizes the silicate glass structure by modulating the local structure of lithium atoms in Li₂O–Ta₂O₅–SiO₂ ternary glass system. The compositional dependence of structure in lithium tantalum silicate glasses is quantitatively determined based on the structure of the nearest neighbor congruent compound through the lever rule. These findings offer a precise prediction of tantalum silicate glass properties with quantitative control over local structural environment of the disordered materials.     

Elucidating the influences of Tantalum (V) oxide in Bi2O3–TeO2–ZnO ternary glasses: An experimental characterization study on optical and nuclear radiation transmission properties of high-density glasses

We report the optical and experimental gamma-ray and neutron attenuation properties of tantalum pentoxide reinforced Bi₂O₃–TeO₂–ZnO ternary glasses with a nominal composition of 10Bi₂O₃–70TeO₂-(20-x)ZnO-xTa₂O₅ (where x = 0,2,4, and 6 mol%). Measurements of transmittance and absorbance spectra for all of the synthesized samples are performed with Analytik Jena Specord 210 plus device between the range of 190–1100 nm. Moreover, ¹³³Ba and ²⁴¹Am/Be sources are utilized for experimental gamma-ray and neutron attenuation studies of BTZT glasses. According to results, the absorption edge is consistently moved from 380 nm to 390 nm as a result of ZnO/Ta₂O₅ translocation. In addition to decrease in optical band gap values of glass series, the fact that doping the structure containing Ta₂O₅ is lead to an increase in Urbach energies. The obtained irregularity through an increasing Ta₂O₅ additive is also changed the overall nuclear radiation attenuation properties of the BTZT glasses. The gamma-ray attenuation properties are obviously enhanced within the energy range of ¹³³Ba radioisotope. The attenuation properties against fast neutron emitted from ²⁴¹Am/Be were significantly enhanced through increasing Ta₂O₅ contribution. It can be concluded that BTZT6 glass sample may be regarded as a beneficial glass composition for multifunctional applications. It can be also concluded that ZnO/Ta2O5 translocation in Bi₂O₃–TeO₂–ZnO ternary glasses may be regarded as a monotonic tool where the neutron attenuation properties should be strengthened in addition to gamma attenuation properties.     

Transport of potassium ions in niobium phosphate glasses

The influence of Nb₂O₅ on the structure and ionic conductivity of potassium phosphate glasses was investigated in glasses with composition xNb₂O₅–(100-x)[0.45K₂O–0.55P₂O₅], x = 10–47 mol%. The Raman spectra of glasses reveal a transition from predominantly orthophosphate to predominantly niobate glass network with increasing Nb₂O₅ content. In the glass structure, niobium forms NbO₆ octahedra which are interlinked with phosphate units for the glass containing 10 mol% Nb₂O₅, but for higher Nb₂O₅ content they become mutually interconnected via Nb-O-Nb bonds. The transport of potassium ions was found to be strongly dependent on the structural characteristics of the glass network. While the mixed niobate-phosphate glass network hinders the diffusion of potassium ions by providing traps that immobilize them and/or by blocking the conduction pathways, predominantly niobate glass network exhibits a rather facilitating effect which is evidenced in the trend of DC conductivity as well as in the features of the frequency-dependent conductivity and typical hopping lengths of potassium ions.     

Enhanced energy storage and discharge-charge performance by changing glass phase content in potassium sodium niobate glass-ceramics

(1-x) (K₂O–Na₂O–2Nb₂O₅)-x (2BaO–Nb₂O₅–2SiO₂) glass-ceramics with x = 0.10, 0.15, 0.20, 0.25 have been successfully prepared by traditional melting method. XRD and microstructure analysis demonstrate that all glass-ceramics are crystallized into uniform Na_0.9K_0.1NbO₃ and K₂(NbO)₂(Si₄O₁₂) ferroelectric crystalline phase. Increasing x promotes the formation of Ba₂NaNb₅O₁₅ phase with a tungsten bronze structure. Raman and complex impedance data confirmed that Ba²⁺ is introduced to repair the disruption of the glass network and make carrier migration difficult when x = 0.15. Thus, the x = 0.15 glass-ceramic sample possesses a maximum calculated energy storage density of 2.32 J/cm³ under 820 kV/cm because of a high degree of polymerization (DOP) glass network structure. Moreover, the pulsed discharge-charge tests are carried out to evaluate actual energy storage performance.     

BNT-based ferroelectric ceramics: Electrical properties modification by Ta2O5 oxide addition

Due to their superior piezo-responses (strain S > 0.3%), bismuth sodium titanate (BNT)-based relaxor ferroelectrics have received much attention. Compared to other chemical elements, tantalum (Ta) doping provides superior electro-strain for these ferroelectrics, while the effect of Ta₂O₅ as oxide additive has been rarely reported. Herein, lead-free piezoceramics of Bi_0.5(Na_0.72K_0.22Li_0.06)_0.5TiO₃-xTa₂O₅ (BNKLT-xTa₂O₅, x = 0-0.015) are synthesized. We study the effects of Ta₂O₅ addition on the crystal structure, piezoelectric responses, dielectric properties, and ferroelectric properties of BNKLT ceramics. All of the ceramics exhibit a typical perovskite structure, and Ta₂O₅ diffuses into the BNKLT lattice to form a uniform solid solution. The addition of Ta₂O₅ can make the grains more regular and uniform, while excess Ta₂O₅ result in finer grains. The undoped BNKLT ceramics show good ferroelectric and piezoelectric properties (remnant polarization P_r = 22.5 μC/cm² and piezoelectric coefficient d₃₃ = 250 pC/N); however, the addition of Ta₂O₅ leads to an clear degradation in d₃₃ and P_r. Meanwhile, the addition of an appropriate Ta₂O₅ amount leads to an increase in the electro-strain, and the unipolar strain reaches 0.385% under 60 kV/cm for x = 0.003, together with a higher normalized strain (d₃₃^*=S_max/E_max) of 633 pm/V (x = 0.003). The enhanced strain behaviors can be attributed to the coexistence of the ferroelectric and relaxor states, and an excellent electrostriction coefficient Q₃₃ (Q₃₃ = S/P²) value of 0.038 m⁴C⁻² is obtained under 60 kV/cm for x = 0.003.     

Effect of Ta2O5 addition on the structure,crystallization mechanism,and properties of CaO–B2O3–SiO2 glasses for LTCC applications

CaO–B₂O₃–SiO₂–Ta₂O₅ (CBST) glass-ceramics, with different Ta₂O₅ content, (up to 6 mol%), have been prepared by using glass melt quenching followed by heat treatment between 800 and 880 °C. The Fourier Transform Infrared (FTIR) results showed that the stronger the attraction of Ta⁵⁺ to the oxygens in the BO₃^3? and SiO₃^2? structures, the more easily the B–O and Si–O bonds will be destroyed. The underlying reason is most probably the high field strength of Ta⁵⁺, which results in a weakening of the vibration intensities of the [BO₃] and [SiO₄] units. Moreover, the Differential Scanning Calorimetry (DSC) results showed that the softening point (T_g), crystallization starting temperature (T_c1), and exothermic crystallization peak temperature (T_p1), of the CaSiO₃ phase, shifted to higher values with the addition of Ta₂O₅. Also, the crystallization activation energy (E_a) and the glass stability factor (ΔT) of the CaSiO₃ phase increased, which indicated that the CaSiO₃ phase of the glass became inhibited by the addition of Ta₂O_5. It was, thus, obvious that there was a need of glass characterization. The results of the crystallization kinetics showed that the critical cooling rate decreased with the addition of Ta₂O₅, which indicated that the viscosity of the system had increased. The CBST glass-ceramics, containing 1 mol% Ta₂O_5, that were sintered at 875 °C for 15 min showed excellent dielectric properties: ε_r = 6.22 and tanδ = 1.19 × 10^?3 (1 MHz). To sum up, CaO–B₂O₃–SiO₂–Ta₂O₅ glass-ceramics are potential low temperature co-fired ceramic substrate materials.     

Second harmonic generation in germanotellurite bulk glass‐ceramics

In this study, we have investigated the use of silver cation as nucleating agent in germanotellurite glass matrix of compositions (100?x) [70TeO₂–10GeO₂–10Nb₂O₅–10K₂O]–xAg₂O (x=0‐6 mol%), in order to promote bulk crystallization. Density measurements, differential scanning calorimetry, X‐ray diffraction, UV‐Vis, and Raman spectroscopies have been performed to study the crystallization process. We have observed bulk crystallization of a unique noncentrosymmetric phase, K[Nb_1/3Te_2/3]₂O_4.8, which has been investigated for its second‐order optical activity. Transparent to translucent glass‐ceramics have been successfully tailored under thermal treatment and second harmonic generation signals were recorded on the glass‐ceramic samples as a function of their synthesis procedure. It is suggested that the second‐order optical properties observed are strongly related to the organization of crystallites within phase‐separated domains.     

Hydrothermal synthesis and piezoelectric property of Ta-doping K0.5Na0.5NbO3 lead-free piezoelectric ceramic

Ta-doping K_0.5Na_0.5Nb_1−xTa_xO₃ (x = 0.1, 0.2, 0.3, 0.4) powder was synthesized by hydrothermal approach and its ceramics were prepared after sintering and polarizing treatment in this work. The K_0.5Na_0.5Nb_0.7Ta_0.3O₃ ceramics near morphotropic phase boundary (MPB), which exhibited optimum piezoelectric properties of d₃₃ = 210 pC/N and good electromechanical coupling factors of K_p = 0.3. The domain structure has been observed from TEM images which indicates that the K_0.5Na_0.5Nb_0.7Ta_0.3O₃ ceramics have good piezoelectric and ferroelectric properties for it is near the MPB.     

Design on improving piezoelectric strain and temperature stability of KNN-based ceramics

Lead-free 0.99(0.96K_0.46Na_0.54Nb_1-xTa_xO₃-0.04Bi_0.5(Na_0.82K_0.18)_0.5ZrO₃)-0.01CaZrO₃ (0.99(0.96KNNTax-0.04BNZ)-0.01CZ) ceramics were prepared by a solid-state sintering method. Ta₂O₅ doped in the 0.99(0.96KNNTax-0.04BNZ)-0.01CZ ceramics results in a phase structure transition from the orthorhombic (O)/tetragonal (T) phase to the rhombohedral (R)/T phase. The Ta₂O₅ dopant induces a decrease in the average grain size from ~1.70 to ~0.69 μm. At x = 0.02 and 0.04, the ceramics have a high reverse piezoelectric coefficient (~500 pm/V under 25 kV/cm). The ceramics with x = 0.04 show an optimal level of unipolar strain, reaching 0.17% under 35 kV/cm at room temperature, and their field-induced strain varies <10% in the temperature range from 25 to 135°C. The presence of the O phase in the polymorphic phase boundary (PPB) improves the temperature stability the reverse piezoelectric coefficient (). Obtaining KNN-based ceramics with good piezoelectric properties and weak temperature sensitivity by designing a R/O/T phase boundary and controlling the average grain size to the submicrometer level is highly feasible.     

Microstructural characterization and crystallization kinetics of (1 − x)TeO2–xK2O (x = 0.05, 0.10, 0.15, 0.20 mol) glasses

Microstructural characterization and crystallization kinetics of (1 − x)TeO₂–xK₂O (x = 0.05, 0.10, 0.15, and 0.20 in molar ratio) glasses were investigated using DTA, XRD, Raman spectroscopy, optical microscopy and SEM techniques. Whereas only one exothermic peak was observed for the 0.95TeO₂–0.05K₂O and 0.90TeO₂–0.10K₂O glasses, two crystallization peaks were present on the DTA plots of the 0.85TeO₂–0.15K₂O and 0.80TeO₂–0.20K₂O glasses. On the basis of the XRD and Raman spectrophometry investigations, α-TeO₂, γ-TeO₂ and K₂Te₄O₉ crystal phases were present in the (1 − x)TeO₂–xK₂O (x = 0.05, 0.10, 0.15, and 0.20 in molar ratio) glass samples heated above the peak crystallization temperatures, T_p. SEM/EDS investigations of (1 − x)TeO₂–xK₂O (x = 0.05, 0.10, 0.15, and 0.20 in molar ratio) glasses heated above T_p revealed the presence of distinct TeO₂-rich and K₂Te₄O₉ in the 0.95TeO₂–0.05K₂O and triangular wedge-shaped crystalline regions in the 0.90TeO₂–0.10K₂O, 0.85TeO₂–0.15K₂O and 0.80TeO₂–0.20K₂O glasses. DTA analyses were carried out at different heating rates and the Avrami constant for the 0.95TeO₂–0.05K₂O glass was calculated as 0.94, an indication of surface crystallization also confirming SEM results. On the other hand, the n values were between 1.7 and 1.87 for the exothermic peaks of the 0.80TeO₂–0.10K₂O, 0.85TeO₂–0.15K₂O and 0.80TeO₂–0.20K₂O glasses, indicating one-dimensional crystalline growth mechanisms for these glasses. Activation energies for one-dimensional crystal growth mechanisms in these crystals determined from the modified Kissinger plots were found to vary between 550 and 650 kJ/mol.     

Influence of Ge and GeO2 on the microstructure and varistor properties of TiO2–Ta2O5–CaCO3 ceramics

This study investigated the effect of elemental crystal Ge or/and GeO₂ doping on the microstructure and varistor properties of TiO₂–Ta₂O₅–CaCO₃ varistor ceramics, which were prepared via the traditional ball milling–molding–sintering process. X-ray diffraction, scanning electron microscopy, scanning transmission electron microscopy-energy dispersive X-ray spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy demonstrated that co-doping with Ge and GeO₂ changed the microstructure of TiO₂–Ta₂O₅–CaCO₃ ceramics, thereby increasing the nonlinear coefficient and decreasing the breakdown voltage. The optimum doping concentrations of Ta₂O₅, CaCO₃, Ge, and GeO₂ exhibited the highest nonlinear coefficient (α=14.6), a lower breakdown voltage (E_B=18.7 V mm⁻¹), the least leakage current (J_L=10.5 μA cm⁻²), and the highest grain boundary barrier (Φ_B=1.05 eV). In addition, Ge and GeO₂ function as sintering aids, which reduce the sintering temperature because of their low melting points.     

Extended X-ray absorption fine structure,X-ray diffraction and Raman analysis of nickel-doped Ba(Mg1/3Ta2/3)O3

Raman, X-ray diffraction and extended X-ray absorption fine structure (EXAFS) measurements of xBa(Ni_1/3Ta_2/3)O₃ + (1 − x)Ba(Mg_1/3Ta_2/3)O₃ samples with x = 0–0.03 were performed to reveal the nickel doping effect on the microwave properties. EXAFS result clearly shows that the nickel is located on the Mg lattice site. We also found that, as the nickel concentration increases, microwave dielectric constant decreases with the TaO and NiO bond distances. X-ray diffraction shows that the 1:2 ordered structure is degraded with the increasing of nickel concentration. The stretching phonon of the TaO₆ octahedra, that is A_1g(O) phonon near 800 cm⁻¹, are strongly correlated to the microwave properties of xBa(Ni_1/3Mg_2/3)O₃ + (1 − x)Ba(Mg_1/3Ta_2/3)O₃ samples. The large Raman shift and the large width of the A_1g(O) imply rigid but distorted oxygen octahedral structure, therefore, the effect of nickel doping lowers the dielectric constant and the Q × f value of Ba(Mg_1/3Ta_2/3)O₃ ceramic.     

Eu3+‐Activated Borogermanate Scintillating Glass with a High Gd2O3 Content

Eu³⁺‐activated borogermanate scintillating glasses with compositions of 25B₂O₃–40GeO₂–25Gd₂O₃–(10?x)La₂O₃–xEu₂O₃ were prepared by melt‐quenching method. Their optical properties were studied by transmittance, photoluminescence, Fourier transform infrared (FTIR), Raman and X‐ray excited luminescence (XEL) spectra in detail. The results suggest that the role of Gd₂O₃ is of significance for designing dense glass. Furthermore, energy‐transfer efficiency from Gd³⁺ to Eu³⁺ ions can be near 100% when the content of Eu₂O₃ exceeds x = 4, the corresponding critical distance for Gd³⁺–Eu³⁺ ion pairs is estimated to be 4.57 Å. The strongest emission intensities of Eu³⁺ ions under both 276 and 394 nm excitation are simultaneously at the content of 8 mol% Eu₂O₃. The degree of Eu–O covalency and the local environment of Eu³⁺ ions are evaluated by the value of Ω_t parameters from Judd–Ofelt analysis. The calculated results imply that the covalency of Eu–O bond increases with the increasing concentration of Eu³⁺ ions in the investigated borogermanate glass. As a potential scintillating application, the strongest XEL intensity under X‐ray excitation is found to be in the case of 6 mol% Eu₂O₃, which is slightly different from the photoluminescence results. The possible reason may be attributed to the discrepancy of the excitation mechanism between the ultraviolet and X‐ray energy.     

Energetic Effects of Substitution of La–Nd and Si–Ge Oxyapatite‐Type Materials

A series of lanthanide oxyapatites, neodymium silicates (Nd_9.33?xM_3x/2(SiO₄)₆O₂; x = 0.0 and 2.0 and M = Ca, Sr, and Ba), and lanthanum germanate (La₁₀(GeO₄)₆O₃) were prepared by a variety of heat treatments and characterized. High‐temperature oxide melt solution calorimetry in molten 2PbO–B₂O₃ solvent at 1078 K was performed to determine their enthalpies of formation from constituent oxides at room temperature. The energetics of these materials is discussed in terms of the effects of doping on two crystallographic sites, the lanthanide and tetrahedral sites. The enthalpy of formation from oxides becomes less exothermic by substituting La with Nd throughout the whole series, in both doped and undoped compositions, reflecting the smaller radius and lower basicity of Nd compared with La. Cation stoichiometric lanthanum germanate apatite (La₁₀(GeO₄)₆O₃) shows a more endothermic enthalpy of formation than the corresponding silicate, reflecting the larger radius and lower acidity of Ge than Si.     

Optimization of electrical conductivity in the Na2O-P2O5-AlF3-SO3 glass system

We report on the individual roles of charge carrier density and network modification in sodium ion conducting glasses from the Na₂O-P₂O₅-SO₃-AlF₃ (NAPFS) system. For this, a broad range of glass compositions was considered across the series of 44Na₂O/(56 – x − y)P₂O₅/xAlF₃/ySO₃, 47Na₂O/(53 − x − y)P₂O₅/xAlF₃/ySO₃, and 50Na₂O/(50 − x − y)P₂O₅/xAlF₃/ySO₃, with x = 8, 12, 16, 20 and y = 0, 5, 7, 10, 12. Impedance spectroscopy was conducted on these glasses at frequencies from 10⁻² to 10⁶ Hz and over temperatures from 50 to 250°C, and complemented by structural analyses using Raman spectroscopy and nuclear magnetic resonance data. While the trends in dc conductivity and activation energy follow that of Na₂O content (increasing from 44 to 50 mol%), substantial enhancement of conductivity (by about two orders of magnitude) and correspondingly lower activation energy were also found for constant Na₂O concentration when adjusting SO₃ or AlF₃ within specific limits of glass structure.