Increasing Sb2O3 Content Research Articles

Enhanced soft piezoelectric properties of Sb2O3 doped 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 materials

In this paper, we have studied the soft piezoelectric properties of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 doped with Sb2O3. The optimal piezoelectric charge constant and dielectric permittivity of the calcined and sintered 0.5Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 were determined by varying the Sb2O3 content. The mol% of Sb2O3 was set to 0, 0.05, 0.1, 0.15, and 0.2, and the doped ceramics were sintered at a temperature of 1475 °C. The piezoelectric charge constant d33, electromechanical coupling coefficient kp, and dielectric permittivity εr of the doped ceramics increased with the increasing Sb2O3 content, whereas their Curie temperature Tc slightly decreased. At 0.1 mol% of Sb2O3, the highest piezoelectric charge constant, electromechanical coupling coefficient, and dielectric permittivity values were obtained. Although the Curie temperature was slightly lowered, the dielectric permittivity improved. 0.5BZT-0.5BCT doped with Sb2O3 exhibited a high remnant polarization Pr even when a weak coercive electric field Ec was applied, resulting in an easy polarization. It can be seen that the improved electrical properties and the behavior of the P-E hysteresis loop through the dopant addition of Sb2O3 are close to the soft piezoelectric characteristics. Thus, the synthesized lead-free and Sb2O3-doped ceramics, with excellent piezoelectric properties and depolarization behaviors, are expected to replace lead-based ceramics and will be useful in energy converters, such as piezoelectric transformers.

Developing effective gamma and X‐ray shielding materials: Thermoplastic natural rubber composites with antimony oxide

AbstractThermoplastic natural rubber (TPNR) based on polybutylene adipate terephthalate (PBAT)/natural rubber (NR) has been prepared to develop flexible radiation shielding materials by adding antimony oxide (Sb2O3). TPNR composites were prepared with a composition of NR 40% and PBAT 60%, at various loading levels of antimony oxide. The properties of the resulting composites, such as tensile strength, elongation at break, hardness, and specific gravity of TPNR composites, were investigated. Gamma‐ray shielding properties were measured under the exposure of gamma rays in the energy range of 0.223–0.662 MeV by Compton scattering technique. X‐ray shielding properties were measured with a high‐frequency digital radiography X‐ray machine at 70–120 kVp and 40 mAs. The results show that the gamma‐ray shielding properties, such as the values of mass attenuation coefficient (μm), effective atomic number (Zeff), and effective electron density (Neff) of materials, increased with increasing amounts of Sb2O3. Similar results were observed for X‐ray shielding properties. The half‐value layer (HVL) values of all samples decreased with increasing Sb2O3 content. The obtained results confirm that TPNR/Sb2O3 can be effectively used as an alternative flexible radiation shielding material.

Enhancing the physical, optical and shielding properties for ternary Sb2O3–B2O3–K2O glasses

Ternary Sb2O3–B2O3–K2O glass system, with general composition of x Sb2O3–(70-x) B2O3–30 K2O (where x = 0, 10, 20, 30, 40, 50) were prepared using melt-quenching technique. Structures of these glasses were investigated using XRD analysis and FT-IR spectroscopy. The optical properties were investigated using the UV–Vis NIR JASCO (Model V-670) Double Beam Spectrophotometer. Different physical parameters, such as density (ρ), molar volume (VM), oxygen molar volume (VO) and oxygen packing density values (OPD) have been estimated. Also, the Gamma radiation shielding ability have been characterized for the investigated glasses using Phy-X/PSD software in the photon energy range (0.015–15 MeV). XRD analysis confirm the amorphous nature of the prepared glasses. The optical energy gap of SBK glasses is decreasing from 4 to 2.63 eV with increasing Sb2O3 content while refractive index is increasing from 2.17 to 2.5 because of increasing the non-bridging oxygens (NBOs) in the glass matrix. The molar refractivity (Rm), molar polarizability (αm) and the third-order nonlinear optical susceptibility values χ3 have been calculated, their values are found to increase with increasing Sb2O3 content. Glass density and molar volume values for the SBK glasses increase with increasing Sb2O3 content. Increasing the Sb2O3 concentration enhance the radiation shielding features of the prepared glasses against gamma rays and neutrons. Hence, the mass attenuation coefficient (MAC) increases from 8.6 to 35.4 cm2/gm while the half value layer (HVL) decreases from 0.036 to 0.0046 cm at 0.015 MeV as the Sb2O3 concentration increases from 0 to 50 mol%. The fast neutron cross section of the six investigated SBK glasses are (0.087, 0.092, 0.095, 0.091, 0.094 and 0.092 cm−1), respectively.

Structure and related physical properties of Li2O-Sb2O3-B2O3 glasses

Glasses of the formula 40Li2O·xSb2O3·(60–x)B2O3 (0 ≤ x ≤ 40 mol%) were prepared using the melt quenching technique. XRD, FTIR spectroscopy, SEM, density and dc conductivity were studied. A phase separation was observed in as-prepared glass samples that contain a concentration of Sb2O3 ≥ 25 mol%. Moreover, crystalline phases of Li5Sb3O8, Li3SbO4 and LiSbO3 were found in the 40Li2O·40Sb2O3·20B2O3 glass sample after thermal treatment at 600 °C for 4 h. N 4 decreased slightly with increasing Sb2O3 content. The contribution to N 4 from Li2O and Sb2O3 was separated. The negative contribution of Sb2O3 to N 4 was due to the association of Sb2O3 and Li2O to form Li5Sb3O8, Li3SbO4 and LiSbO3 phases and acting as a former. The formed Li5Sb3O8, Li3SbO4 phases having low migration energy and rich with Li+ ions exhibited a high mobility. Density and molar volume increased with increasing Sb2O3 content. The abrupt increase in the conductivity by about 4 orders in magnitude for Sb2O3 ≥ 25 mol% is correlated with the presence of clusters rich by Li+ and Sb+3 ions that have low migration energies and the increase in the free volume.

Analyses of defect distributions in ZnO varistors based on the Jonscher’s universal power law and the Dissado–Hill model

The defect distributions in ZnO varistors mixed with Bi2O3, NiO, MnCO3, Co2O3, and SiO2 after doping Sb2O3 were investigated, based on the Jonscher’s universal power law and the Dissado–Hill model. The microstructures were investigated using x-ray diffractometer, scanning electron microscope, energy dispersive spectrometer, and x-ray photoelectron spectrometer. The capacitance–voltage (C–V) method was utilized to obtain the parameters of the double Schottky barrier. The dielectric spectra were analyzed to extract the parameters of defect distribution. The current density–electric field (J–E) characteristics were measured to obtain the parameters of electrical properties. We found that with increasing Sb2O3 content, the ZnO grain size distribution become more homogeneous in the Sb2O3-doped ZnO varistors; the density is decreased; except for less homogeneous , more homogeneous distributions of in the depletion layers and the extrinsic defects at the interfaces are achieved in the Sb2O3-doped ZnO varistors. Therefore, the enhancement in the electrical properties was achieved by doping Sb2O3 due to the increased number of active grain boundaries per unit volume, i.e. the increased breakdown field and nonlinear coefficient, and the decreased leakage current density. The results of this study suggest that the Jonscher’s universal power law and the Dissado–Hill model can be effectively used to analyze defect distributions in varistor ceramics.

Hydrophobic nanocrystalline glazes based on cassiterite for self-cleaning outdoor power grid insulators

Self-cleaning hydrophobic glazes were prepared using a base industrial glaze. A semiconducting component (95SnO2.xSb2O3.(5-x)NiO, where x = 0–5), in which cassiterite nano-sized needles were crystallized was added to the base glaze. The glazes (named SbxNi(5-x)) were applied on a porcelain insulator and gloss fired in an industrial furnace at 1310 °C. The water contact angle (WCA), electrical resistivity and band gap of the glazes were measured. The most decisive factors in the resulted properties were the amount and composition of the semiconducting component and the morphology of the crystallized cassiterite phase. With increasing Sb2O3 content, the crystallinity increased and the needles became shorter and smaller resulting in a higher specific surface area, encouraging air buckets entrapment, and therefore the highest WCA of 147.9˚. This sample also demonstrated the lowest resistivity (28.35 MΩ.cm), due to the presence of maximum Sb ions as electron donors, creating the lowest band gap (2.5 eV). On the contrary, the sample Sb4Ni1 showed the highest resistivity; this was due to the reduction of mobility as a result of the presence of very larger Sb ions in the cassiterite structure with smaller Sn ions, causing charge carrier scattering.

Structural, magnetic and theoretical investigation of the magnetocaloric effect of La0.6Sr0.4MnO3/x(Sb2O3) compound

ABSTRACT We report the structural and magnetocaloric properties of the perovskite manganite composites (La0.6Sr0.4MnO3)/x(Sb2O3) (LSMO/Sb2O3) (x = 0.07 and 0.18) synthesized by the solid-state reaction method. X-ray diffraction (XRD) study was employed to confirm the formation of both the phases in composites. The results of magnetic measurements indicate that Sb2O3 mainly segregates at the grain boundaries of LSMO. Arrott analysis and master curve behavior reveal a second-order magnetic phase transition in the composite samples. Magnetic entropy change increases with increasing Sb2O3 content and a maximum of 3 J/kg. K at 2 T has been observed in the LSMO/(0.18) Sb2O3 sample. The enhanced ΔSM of these composites makes them attractive for potential applications.

Composition-structure-property effects of antimony in soda-lime-silica glasses

Float glass-type SiO2-Na2O-CaO glasses with 0 – 10 mol% Sb2O3 were melted and their compositional, structural, thermal and optical properties characterised. All glasses were X-ray amorphous and increasing Sb2O3 content progressively decreased glass transition temperature (Tg) and dilatometric softening point (Td), despite increases in Al2O3 content from greater crucible corrosion. 121Sb Mössbauer spectroscopy confirmed that Sb was predominantly incorporated as Sb3+ (Sb3+/ΣSb ~ 0.9) and Raman spectroscopy showed that Sb substantially decreased average (Si, Al)-O Qn speciation. Both techniques confirmed that Sb3+ ions were incorporated in trigonal pyramidal [:SbO3] polyhedra. XRF and Raman spectroscopies confirmed that SO3 content decreased with increasing Sb2O3 content. TGA analysis showed, as a linear function of Sb2O3 content, mass gain commencing at 700°C, reaching a maximum at 1175°C, then mass loss above 1175°C, consistent with oxidation (Sb3+ → Sb5+) then reduction (Sb5+ → Sb3+). The TGA samples were shown to have attained or approached Sb redox equilibrium during measurement. Optical absorption spectroscopy (UV-Vis-nIR) showed red-shifts of the UV absorption edge with increasing Sb2O3 content, consistent with increasing intensity of far-UV absorption bands from Sb3+ and Sb5+ s→p transitions. UV-Vis-nIR fluorescence spectroscopy evidenced a broad luminescence band centred at ~25,000 cm−1, attributed to the 3P1→1S0 transition of Sb3+, which is Stokes shifted by ~15,000 cm−1 from the 1S0→3P1 absorption at ~40,000 cm−1. The most intense emission occurred at 0.5 mol% Sb2O3, with concentration quenching reducing luminescence intensities at higher Sb2O3 contents. Additions of Sb2O3 to float-type soda-lime-silica glasses could thus enable lower melting energies and/or new solar energy applications.

Structural investigation and properties of Sb2O3–PbO–B2O3 glasses

XRD patterns indicate that the glasses xSb2O3⋅(40 − x)PbO⋅60B2O3⋅0.5CuO and xSb2O3⋅40PbO⋅(60 − x)B2O3⋅0.5CuO have amorphous structure for 0 ≤ x ≤ 40 mol%. The fraction (N4) of four coordinated boron atoms of both series decreases with increasing Sb2O3 content. The density decreases in the first series, whereas it increases in the second one. The contribution to N4 from PbO and Sb2O3 in each series could be separated. Sb2O3 contributes negatively to N4 in the second series, which is attributed to association of Sb2O3 and PbO forming Pb2Sb2O7 phase. Calculated densities agree well with the experimental data of the first series. Calculated densities could be obtained from the concentration of various structural units in glasses, as predicted from N4 data. Glasses in the second series have strong tendency to crystallization when heat treated. This tendency is not observed in the first series. These effects are explained by considering the abundance of B2O3 in glass.

Theoretical and experimental study of PbO-SiO2-Sb2O3 glasses as gamma ray shielding materials

Investigation and application of high energy radiations require the availability of radiation shields. In this research, glasses with the composition of 0.65PbO.(0.35-x)SiO2.xSb2O3 (x = 0, 0.01, 0.02, 0.03, 0.04, 0.05) were fabricated and characterized using densitometry, XRD, UV-Vis spectrophotometry and gamma ray spectrometry. The theoretical attenuation coefficient of the samples was calculated using WinXCom software. It was observed that although PbO strongly increased the mass attenuation coefficient for Co-60 radiation of glass, its substitution by Sb2O3 initially increased the parameter from 0.0609 to 0.0621, due to the dominant effect of Sb2O3 on bubble removal. The results also showed that there was an inconsistency between the theoretical and empirical results, that is, with increasing Sb2O3 content of the samples, the attenuation coefficient initially increased and then decreased, while the theoretical calculations predicted a continuous decline. It appears that the disagreement is mainly due to the fining effect of Sb2O3 and its effects on the bubble content. The WinXCom software is designed to work solely based on the mixture law. The sample 0.65PbO.0.34SiO2.0.01Sb2O3 showed the highest mass attenuation. The coefficient was 0.0621 and 0.0609 in 1.250 MeV for the samples with x = 0 and 0.01.

Dielectric properties and point defect behavior of antimony oxide doped Ti deficient barium strontium titanate ceramics

Abstract The microstructures and dielectric properties of Sb2O3-doped Ti deficient barium strontium titanate ceramics prepared by solid state method were investigated with non-stoichiometric level and Sb2O3 content by SEM, XRD and LCR measure system. It is found that with the increase of δ, (Ba0.75Sr0.25)Ti1–δO3–2δ ceramics transform from single phase solid solutions with typical cubic perovskite structure to multiphase compounds while (Ba0.75Sr0.25)Ti0.998O2.996 ceramics remain to be single-phase with the increasing Sb2O3 content. The distortion of the ABO3 perovskite lattice caused by VTi″″ and Vo•• induces the drop of Curie temperature and the rise of relative dielectric constant in (Ba0.75Sr0.25)Ti1–δO3–2δ ceramics with increasing δ value. The orientation of Vo•• elastic dipoles results in the domain-wall pinning and thus the reduction of the dielectric loss. With increasing Sb2O3 content, the relative dielectric constant, dielectric constant maximum and Curie temperature of (Ba0.75Sr0.25)Ti0.998O2.996 ceramics decrease dramatically while the dielectric loss increases.

Effect of antimony-oxide on the shielding properties of some sodium-boro-silicate glasses

Some sodium-silicate-boro-antimonate glasses having the molecular composition [(20) Na2O – (20) SiO2 – (60-x) B2O3 – (x) Sb2O3 (where x takes the values 0, 5 … or 20)] have been prepared by the melt quenching method. The melting and annealing temperatures were 1500 and 650K respectively. The amorphous nature of the prepared samples was confirmed by using X-ray diffraction analysis.Both the experimental and empirical density and molar volume values showed gradual increase with increasing Sb2O3 content. The empirical densities showed higher values than those obtained experimentally, while the empirical molar volume values appeared lower than those obtained experimentally, which confirm the amorphous nature and randomness character of the studied samples.The experimentally obtained shielding parameters were approximately coincident with those obtained theoretically by applying WinXCom program. At low gamma-ray energies (0.356 and 0.662MeV) Sb2O3 has approximately no effect on the total Mass Attenuation Coefficient, while at high energies it acts to increase the total Mass Attenuation Coefficient gradually. The obtained Half Value Layer and Mean Free Path values showed gradual decrease as Sb2O3 was gradually increased. Also, the Total Mass Attenuation Coefficient values obtained between about 0.8 and 3.0MeV gamma-ray energy showed a slight decrease, as gamma-ray photon energy increased. This may be due to the differences between the Attenuation Coefficients of both antimony and boron oxides at various gamma-ray photon energies.However, it can be stated that the addition of Sb2O3 into sodium-boro-silicate glasses increases the gamma-ray Attenuation Coefficient and the best sample is that contains 20 mol% of Sb2O3, which is operating well at 0.356 and 0.662MeV gamma-ray.

Sb2O3 doped and microwave assisted sintering of ITO

Indium tin oxide (ITO) ceramics with high densities are difficult to achieve using conventional heating because of the volatilisation of both indium oxide and tin oxide at high temperatures. In our present study, we proposed to use a Sb2O3 doped and microwave hybrid sintering approach to prepare for ITO ceramics. The effects of the Sb2O3 content on the microstructure, densification and electrical properties of ITO ceramics were investigated. The results show that the relative density has reached 98·3% by using the hybrid sintering approach. The resistivity of the obtained ceramics showed a decrease tendency with increasing Sb2O3 content in the range of 0–1·5 wt-%. We speculate that the formation of electrons and vacancies caused by the doping of Sb2O3 and the ‘microwave effect’ might be the main reason responsible for the increase in the densification. As a result, these, in turn, further enhanced the electronic conductivity of the obtained ITO ceramics.

Glass transition and fragility of telluro-vanadate glasses containing antimony oxide

The activation energy (ΔH *) of the glass transition and the heating-rate dependence of the glass transition temperature (T g) of V2O5–Sb2O3–TeO2 glasses were determined using differential scanning calorimetry technique. Non-isothermal measurements were performed at different heating rates φ (=3, 6, 9, 10, 13 K/min). The heating rate dependence of T g was used to investigate the applicability of different theoretical models describing the glass transition. The application of Moynihan and Kissinger et al. models to the present data led to different values of (ΔH *) at each different heating-rate regions. This behavior was attributed to the strong heating rate dependence of the activation energy of the process. The fragility parameter (m = ΔH */RT g) were ≲90, suggesting that these glasses may be classified as strong glasses. The viscosity, η, calculated at a few selected temperatures near the glass transition region increased with increasing Sb2O3 content at any given temperature, which is also expected. Also the compositional dependence of T g and ΔH * was investigated.

Glasses formation, characterization, and crystal-structure determination in the Bi2O3-Sb2O3-TeO2 system prepared in an air.

A glass-forming domain is found and studied within Bi2O3–Sb2O3–TeO2 system. The glasses composition were obtained in pseudo-binary xSbO1.5, (1−x)TeO2 for 0.05 ≤ x ≤ 0.20. The constitution of glasses in the system Sb2O3–TeO2 was investigated by DSC, Raman, and Infrared spectroscopy. The influence of a gradual addition of the modifier oxides on the coordination geometry of tellurium atoms has been elucidated based Infrared and Raman studies and showed the transition of TeO4, TeO3+1, and TeO3 units with increasing Sb2O3 content. XRD results reveal the presence of three crystalline: γ-TeO2, α-TeO2, and SbTe3O8 phases during the crystallization process. The density of glasses has been measured. The investigation in the ternary system by the solid state reaction using XRD reveals the existence of a solid solution Bi1−xSb1−xTe2xO4 isotopic to BiSbO4 with 0 ≤ x ≤ 0.1.

Optical Properties and Photoactivity of The Pigmentary TiO2 Doped with P2O5, K2O, Al2O3 and Sb2O3

The influence of the increasing content of antimony calculated to Sb2O3 (0.08–0.57 mol%) with the constant amount of the other additives (calculated to P2O5, K2O, Al2O3) on the optical properties and photostability of doped rutile has been investigated. The properties of the obtained TiO2-PKAlSb samples were compared to the commercial TiO2-PKAl composition. The starting material was the concentrated suspension of technical-grade hydrated titanium dioxide (HTD). The dopant agents' solutions were introduced to HTD. Prepared samples were calcined with gradually increasing process temperature. The XRD analysis was used to determine the rutile content in the TiO2 samples. Optical properties of modified titanium dioxide have been determined spectrophotometrically by measuring the colour in the white (brightness, white tone) and grey system (relative lightening power, grey tone). Photostability was characterized by the white lead-glycerin test with UV-Vis light. It was observed that with the increasing content of antimony in rutile TiO2, doped with phosphates, potassium and aluminium, the brightness and grey tone were increasing but white tone decreased. The changes of the relative lightening power values were insignificant. Comparing the samples of TiO2-PKAlSb with the TiO2-PKAl composition it was observed that titanium dioxide doped with antimony had better white and grey tone. The increasing Sb2O3 content in the TiO2 caused the improvement of the photostability.

The Influence of Sb2O3Addition on the Properties of Low‐melting ZnO–P2O5Glasses

The influence of 0–16 mol% Sb2O3substitution for P2O5on the properties of ZnO–P2O5glasses has been investigated. It was shown that Sb2O3could participate in the glass network and thermal stability of the glasses decreased with increasing Sb2O3content. Glass transition temperatureTg, softening temperatureTs, and water durability all decreased firstly (up to 6 mol% Sb2O3added) and then increased. Substitution of 12 mol% Sb2O3led to a 16°C decrease inTgand 30°C decrease inTs, and weight loss of the glass was only 0.42 mg/cm2, which is ∼11 times lower than that of the glass without Sb2O3after immersion in deionized water at 90°C for 1 day. The glass containing 12 mol% Sb2O3might be a substitute for Pb‐based glasses in some applications.

Fabrication and properties of novel low-melting glasses in the ternary system ZnO–Sb2O3–P2O5

Glasses in the ternary system ZnO–Sb2O3–P2O5 were investigated as potential alternatives to lead based glasses for low temperature applications. The glass-forming region of ZnO–Sb2O3–P2O5 system has been determined. Structure and properties of the glasses with the composition (60−x)ZnO–xSb2O3–40P2O5 were characterized by infrared spectra (IR), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results of IR indicated the role of Sb3+ as participant in glass network structure, which was supported by the monotonic and remarkable increase of density (ρ) and molar volume (VM) with increasing Sb2O3 content. Glass transition temperature (Tg) and thermal stability decreased, and coefficient of thermal expansion (α) increased with the substitution of Sb2O3 for ZnO in the range of 0–50mol%. XRD pattern of the heat treated glass containing 30mol% Sb2O3 indicated that the structure of antimony–phosphate becomes dominant. The improved water durability of these glasses is consistent with the replacement of easily hydrated phosphate chains by corrosion resistant P–O–Sb bonds. The glasses containing ⩾30mol% Sb2O3 possess lower Tg (<400°C) and better water durability, which could be alternatives to lead based glasses for practical applications with further composition improvement.

Thermal behaviour and fragility of Sb2O3-containing zinc borophosphate glasses

Thermal behaviour of the glass series (100-x)[50ZnO-10B2O3-40P2O5]·xSb2O3 (x=0-42 mol%) and (100-y)[60ZnO-10B2O3-30P2O5]·ySb2O3 (y=0-28 mol%) was investigated by DSC and TMA. The addition of Sb2O3 results in a decrease of the glass transition temperature and crystallization temperature in both compositional series. All glasses crystallize on heating in the temperature range of 522–632°C. Thermal expansion coefficient of the glasses monotonously increases with increasing Sb2O3 content in both series and varies within the range of 6.6–11.7 ppm °C−1. From changes of thermal capacity within the glass transition region it was concluded that with increasing Sb2O3 content the ‘fragility’ of the studied glasses increases.

Relation Between Grain Boundary and Electrical Degradation of ZnO Varistors

The effects of the electrical degradation characteristics and microstructure of Sb2O3-doped ZnO varistors were investigated by optical microscopy, X-ray diffraction (XRD) analysis, and voltage-current (V-I) characteristics analysis. The nonlinearity index α of the V-I characteristics of the Bi-Mn-Co-Sb2O3-doped ZnO varistors decreased with increasing Sb2O3 content after electrical degradation. The twin crystal of ZnO was formed by doping with Sb2O3. The number of twin crystals, of which two c-axes are perpendicular to the twin plane, increased and the number of twin crystals, of which c-axes are parallel to the twin plane, decreased with increasing amount of Sb2O3 doped. It is suggested that electrical degradation is affected by the combination of the orientation of ZnO grains containing twin planes and a double Schottky barrier may not be formed in the twin plane.