Diamagnetic Glasses Research Articles

The structure, spectra and properties of Dy2O3 modified diamagentic lead-bismuth-germanium glasses

Dy2O3 is potential and attractive as scintillator, mid infrared laser and Faraday rotation materials in high energy physics, general radiation and magneto optical sensing systems. In this study, Dy3+ doped diamagnetic glasses with compositions of 10GeO2 – 30PbO – 50Bi2O3 – (10-x)B2O3 –xDy2O3 (x = 0, 0.5, 1, 2, 3, 5 M %) were fabricated by a melt quenching technique. The modification of Dy3+on glass forming, structure, UV–Vis, FT-IR, Raman and photoluminescence spectra and properties were investigated through XRD, Raman spectra, DSC, Vicker's hardness and Verdet constant measurements etc. Melt with Dy2O3 content beyond 5% prefer to crystallize, not to form glassy matrix. The UV visible absorption spectra showed three intense bands at 483 nm, 575 nm and 661 nm due to 4F9/2 → 6H15/2 (blue), 4F9/2 → 6H13/2 (yellow) and 4F9/2 → 6H11/2 (red) transitions, respectively. Judd-Ofelt paramaters have been calculated to verify network connectivity of Dy2O3 doped glasses. FT-IR and Raman spectrum depicted the presence of PbO4, BiO3, GeO6, BO3 frame groups and DyO bonds from cubit Dy2O3. Glass doped with 1%Dy2O3 exhibited promising thermal stability (97 °C), microhardness (480 HV) and magneto-optical activity (0.1864 min/G.cm@532 nm) due to the high optical dispersion, high ion polarizability of Dy3+ ions

Optimization of optical current sensor based on rare‐earth magneto‐optical glass

AbstractCompared to the present diamagnetic glass used in the sensing element of optical current sensors (OCSs), the high‐sensitivity characteristics of the rare‐earth magneto‐optical glass (REMOG) can significantly improve the performance of an REMOG sensing element. The optimization objective of this study was to enhance the sensitivity of the sensing element and reduce linear birefringence. Theoretical analysis and experimental data were combined to study the practical influences of a few factors, such as the size and spatial position of the glass, the wavelength of the incident light, and the rare‐earth doping concentration, on the sensitivity of an OCS sensing element. Finally, an optimal parameter combination was obtained. The experimental results showed that the response sensitivity of the REMOG sensing element is seven times the sensitivity using diamagnetic glass.

Bi0.95Pb0.05Fe0.85Mn0.15O3 nanocrystal tailored Faraday rotation of GeO2-PbO-Bi2O3-B2O3 glass

In this study, multiferroic BiFeO3 nanocrystals with different Pb and Mn contents were synthesized and characterized to determine an optimized composition with high transmittance and good magnetic property. The optimized Bi0.95Pb0.05Fe0.85Mn0.15O3 nanocrystal (BPFMO) was then doped into GeO2-PbO-Bi2O3-B2O3 diamagnetic glass in order to enhance physical properties. The optimize BPFMO doping content was investigated to be 5 mol%, however, glass with 2% BPFMO exhibited the best network connectivity, Vicker's hardness and exciting Faraday rotation performance due to the Mn-tailored low band gap, Pb-enhanced polarization, magnetization, densification of nanoscaled Bi0.95Pb0.05Fe0.85Mn0.15O3.

Improvement of the Faraday effect in Ge-S based chalcogenide glasses via gallium and lead compositional modifications

The diamagnetic performance of GeS2-Ga2S3 and GeS2-Ga2S3-PbI2 chalcogenide glasses were investigated, and the composition, wavelength and temperature dependences of the Verdet constant were discussed in detail. It indicates that the contributions to the Verdet constant for each kind of ion are in the order of VPb>VGa>VGe in these chalcogenide glasses, and the Becquerel rule is proved to be an effective guidance for predicting the Verdet constant value. A large Verdet constant is obtained in 68GeS2·17Ga2S3·15PbI2 composition glass and the value is 0.230 min·G−1·cm−1 at 635nm, which is greatly larger than those of commercial diamagnetic glasses. Besides, the temperature coefficient of Verdet constant can be regarded as a constant between 278 and 368 K, indicating these chalcogenide glasses are good candidates for magneto-optical devices in temperature instability conditions.

Structure, spectra and thermal, mechanical, Faraday rotation properties of novel diamagnetic SeO2-PbO-Bi2O3-B2O3 glasses

Faraday rotation diamagnetic glass has attracted research attentions in photonics, sensing and magneto optical devices due to their high refractive index, wide transmittance in UV and Fourier transform infrared (FT-IR) range and temperature independent Faraday rotation. Selenite modified heavy metal oxides glasses with composition of xSeO2-(10-x) B2O3-45PbO-45Bi2O3 (x = 0, 1, 5 and 10mol%) and 15%SeO2-40%PbO-45%Bi2O3 have been fabricated by melt-quenching method in present study. The influence of SeO2 on glass forming ability, thermal, mechanical properties and Faraday rotation were evaluated through X-ray Diffraction (XRD), Fourier transforms infrared spectra (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), Vicker's hardness and Verdet constant measurements. XRD spectra reveal that the good vitrification was achieved for glass with SeO2 amounts ≤10% even without B2O3. FT-IR, Raman and XPS spectra ascertain the existence of characteristic vibration of SeO4, SeO3, PbO4, BiO3 and BO3 units. The incorporation of SeO2 increases the connectivity of glassy network by increasing the Tg, thermal stability and mechanical hardness. The small band gap, high polarizable Se4+ ions and isolated SeO3 units contribute to Faraday rotation improvement.

SnO2 modified thermal, mechanical and magneto optical property improvement of PbO-Bi2O3-B2O3 glass

SnO2 is a widely accepted room temperature ferromagnetic material and has found applications in rapidly growing fields of spintronics and magneto electronics. Faraday rotation diamagnetic glass has attracted research attentions in photonics, sensing and magneto optical devices due to their high refractive index, wide transmittance in UV and Fourier transform infrared (FT-IR) range and temperature independent Faraday rotation. In this paper, we report for the first time the fabrication of SnO2 modified diamagnetic glass with composition of xSnO2-(10-x) B2O3-30PbO-60Bi2O3 (x = 0, 2, 4, 6, 8 and 10 mol%) by melt-quenching method. The influence of SnO2 on glass forming ability, thermal, mechanical properties and Faraday rotation were evaluated through X-ray Diffraction (XRD), FT-IR, Raman, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), Vicker's hardness and Verdet constant measurements. Good vitrification was achieved with SnO2 amount ≤ 6 mol%. XRD spectra confirmed that too much SnO2 exist as distorted SnO6 polyhedra and there is obvious direct interaction between tin and Bi2O3 structural units. FT-IR, Raman and XPS spectra ascertain the existence of characteristic vibration of SnO4, SnO6, PbO4, BiO3 and BO3 units. Glass with 4%SnO2 exhibited significant good glass thermal stability (102 °C), big Vicker's hardness (369 HV), high Verdet constant (0.1424 min/G.cm at 633 nm) and big cutoff wavelength (432 nm) due to the enhanced network connectivity, brought about by inclusion of high polarization and magnetization strong Sn–O linkages.

Synthesis and properties of nanocrystal BiPO4 in diamagnetic PbO-Bi2O3-B2O3 glass

In this study, we synthesized of BiPO4 nanocrystals in diamagnetic glass (45PbO–45Bi2O3–8B2O3–2P2O5mol %) by melt quenching technique and studied its influence to glass Faraday rotation. The 9nm irregular BiPO4nanocrystals formed in glass and changed glass structure, spectral and properties through the characterization of X-ray diffraction, field Emission scanning electron microscopy, differential scanning calorimetry, UV–Vis optical absorption, Vicker's hardness and Verdet constant etc. The BiPO4 –induced local plasmon effect and bigger polarization gave glass improvements on optical cutoff wavelength, Faraday rotation and Vicker's hardness which is very attractive to magneto optical glass devices.

High Verdet constants and diamagnetic responses of GeS2-In2S3-PbI2 chalcogenide glasses for integrated optics applications.

Chalcogenide glasses as kind of diamagnetic magneto-optical materials have promising applications in the field of integrated optics and optical communication systems due to their excellent properties, such as easy to be processed into waveguide and temperature independence of the Verdet constants. For clarifying the influence factors following the compositional variation on Faraday effect and finding a glass with a large Verdet constant, novel pseudo-ternary chalcogenide glass system, GeS2 - In2S3 - PbI2, was prepared and investigated. The composition, wavelength and temperature dependences on the Verdet constants were systematically investigated at the wavelengths of 635, 808, 980 and 1319 nm. PbI2 was confirmed to have positive contribution to the Verdet constant and the Becquerel rule was proved to be an effective guidance for predicting the Verdet constant in chalcogenide glasses. The 60GeS2·15In2S3·25PbI2 glass was found to possess the largest Verdet constant (V = 0.215 min·G-1·cm-1, @808nm), which is great larger than that of commercial diamagnetic glasses. These glasses also possess good glass-forming ability and VIS-IR transmittance, therefore be a good candidate for next-generation integrated optical isolator and other magneto-optical devices.

Magneto optical properties of rare earth Tb2O3 doped PbO-Bi2O3-B2O3 glass

Terbium dioxide is intensively studied in luminescence and magneto optical applications. The fabrication and characterization of diamagnetic glass with composition of xTb2O3 – 30PbO – 60Bi2O3 – (10−x) B2O3 (x=0, 0.1, 0.2, 0.4, 0.5 and 1mol%) is reported. The influence of Tb2O3 on glass forming ability, glass structure and properties has been studied by means of DSC, XRD, Raman, UV–vis/FTIR spectral and Faraday rotation measurement by a home-made optical bench.Due to the high optical basicity and high polarization of host glass, the formation of Tb4+ in 0.1% Tb2O3 doped PBB glass contributes to an improvement on density, refractive index, thermal stability (106°C), optical cutoff wavelength (501nm) and Verdet constant (0.1301min/G·cm).

Spectra and magneto optical behavior of CeO2 doped heavy metal diamagnetic glass

CeO2 shows interesting redox atmosphere dependent properties and ionic polarizing behavior in glass. In this paper, we report the fabrication and characterization of diamagnetic glass with composition of xCeO240PbO50Bi2O3(10−x) B2O3 (x=0, 0.1, 0.2, 0.4, 0.6 and 1mol%). The Ce3+ and Ce4+ co-existence influences the glass forming ability, glass structure and properties through characterization such as X-ray diffraction, XPS, Raman, UV/ Fourier transforms infrared spectra and Faraday rotation measurement.Due to the high optical basicity and high polarization of host glass, Ce4+ formed in 0.1% CeO2 doped glass and improved the glass thermal stability, optical cutoff and Verdet constant (0.1304min/g·cm).

Magneto‐optical effects of Ge‐Ga‐Sb(In)‐S chalcogenide glasses with diamagnetic responses

AbstractThe Faraday effects of Ge‐Ga‐Sb(In)‐S serial chalcogenide glasses were investigated at the wavelengths of 635, 808, 980, and 1319 nm, respectively. The compositional dependences were analyzed and associated influencing factors including the absorption edge, the concentration of Sb3+/In3+ ions, and the wavelength dispersion of refraction index were discussed. 80GeS2·20Sb2S3 composition glass was found to have the largest Verdet constant (V=0.253, 0.219, 0.149, and 0.065 min·G−1·cm−1 for wavelengths 635, 808, 980, and 1319 nm, respectively) in these glasses, which is larger than that of commercial diamagnetic glasses (Schott, SF 6, V=0.069 min·G−1·cm−1@633 nm, for example). Sb3+ ions with high polarizability possessing s2‐sp electron jumps involving 1S0→1P1, 3P0,1,2 transitions are responsible for large Verdet constant, and Becquerel rule is proved to be an effective guidance for estimating the Verdet constant and further optimizing the compositions in chalcogenide glasses.

Structure, spectra and Faraday rotation in TiO2 doped diamagnetic PbO-Bi2O3-B2O3 glasses

In this paper, we report, for the first time, the Faraday rotation of TiO2 doped diamagnetic glasses with molar composition of 50PbO-40Bi2O3-(10−x)B2O3:xTiO2 (where x=0, 0.2%, 0.5%, 1%, and 2%, respectively). The structure and properties of glasses were characterized by X-ray diffraction (XRD), Raman scattering, UV–Visible absorption, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) etc. A home-made optical bench was constructed for the Faraday rotation measurement.The incorporated TiO2 changed PBB structure by introducing bonding defect and non-bridging oxygen, which accordingly affected the glass forming ability, thermal performance and Faraday rotation. The Verdet constants as a function of laser wavelength, glass cutoff and TiO2 contents were studied, respectively. A yellowish transparent and homogenous glass with a big UV cutoff wavelength (458nm) and a big Verdet constant (0.1634min/G·cm @633nm) was obtained as a good candidate for magneto optical applications.

Surface Plasmon Resonance Enhanced Faraday Rotation in Fe3O4/Ag Nanoparticles Doped Diamagnetic Glass

Diamagnetic TeO2-PbO-B2O3 glasses were melt-quenching fabricated and characterized for Fe3O4/Ag nanoparticles doping through radio-frequency sputtering and thermal treatment techniques. The surface plasmon resonance influenced structure, composition, optical, and magneto optical properties of Fe3O4/Ag doped glasses were investigated through XRD, SEM, XPS analysis, and Faraday rotation measurement. The optimized sputtering and thermal conditions Fe3O4 and Ag nanoparticles were obtained. Under the optimized conditions, a great enhancement of Faraday rotation, thermal property, and big UV cutoff red-shift due to the excited surface plasma’s resonance effect was achieved in diamagnetic glass.

Transition and post-transition metal ions in borate glasses: Borate ligand speciation, cluster formation, and their effect on glass transition and mechanical properties.

A series of transition and post-transition metal ion (Mn, Cu, Zn, Pb, Bi) binary borate glasses was studied with special consideration of the cations impact on the borate structure, the cations cross-linking capacity, and more generally, structure-property correlations. Infrared (IR) and Raman spectroscopies were used for the structural characterization. These complementary techniques are sensitive to the short-range order as in the differentiation of tetrahedral and trigonal borate units or regarding the number of non-bridging oxygen ions per unit. Moreover, vibrational spectroscopy is also sensitive to the intermediate-range order and to the presence of superstructural units, such as rings and chains, or the combination of rings. In order to clarify band assignments for the various borate entities, examples are given from pure vitreous B2O3 to meta-, pyro-, ortho-, and even overmodified borate glass compositions. For binary metaborate glasses, the impact of the modifier cation on the borate speciation is shown. High field strength cations such as Zn2+ enhance the disproportionation of metaborate to polyborate and pyroborate units. Pb2+ and Bi3+ induce cluster formation, resulting in PbOn- and BiOn-pseudophases. Both lead and bismuth borate glasses show also a tendency to stabilize very large superstructural units in the form of diborate polyanions. Far-IR spectra reflect on the bonding states of modifier cations in glasses. The frequency of the measured cation-site vibration band was used to obtain the average force constant for the metal-oxygen bonding, FM-O. A linear correlation between glass transition temperature (Tg) and FM-O was shown for the metaborate glass series. The mechanical properties of the glasses also correlate with the force constant FM-O, though for cations of similar force constant the fraction of tetrahedral borate units (N4) strongly affects the thermal and mechanical properties. For paramagnetic Cu- and Mn-borate glasses, N4 was determined from the IR spectra after deducing the relative absorption coefficient of boron tetrahedral versus boron trigonal units, α = α4/α3, using NMR literature data of the diamagnetic glasses.

Structural, optical and magnetic properties of Fe3O4 sputtered TeO2–PbO–B2O3 and PbO–Bi2O3–B2O3 glasses for sensing applications

The Fe3O4 nanoparticles, incorporated into two diamagnetic glasses (TeO2–PbO–B2O3 and PbO–Bi2O3–B2O3) by DC magnetron sputtering, were annealed at 300°C for 22h in order to investigate the influence to the thermal stability and magneto-optical properties of glasses. The structure, morphology and magnetic properties of two sputtered glasses were compared and characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and UV–VIS spectra measurements. The Verdet constant of glasses was measured by a home-made optical bench.Sputtered samples (Fe3O4 target) were compared with the one obtained by melt-quenching Fe3O4 nanoparticles. The influence of sputtered Fe3O4 layer thickness on thermal and magneto-optical performance was investigated. The results prove that the magnetic property of both glasses, and especially the TeO2–PbO–B2O3 one, is enhanced after the incorporation of 1–5μm-thick-Fe3O4 layer deposited by sputtering. Compared with the uncoated glasses, no significant degradation in FT-IR transmittance, UV–VIS absorption and thermal stability were discovered. The TeO2–PbO–B2O3–Fe3O4 system exhibits the best thermal and magneto-optical performances for magneto optical applications, within the two glass families.

Spatially selective modification of optical and magneto-optical properties in Fe- and Au-doped glasses irradiated with femtosecond-laser

The optical property and the magneto-optical response were space-selectively modified in transparent Fe3+- and Au3+-doped glasses by using infrared femtosecond- (fs-) laser irradiation and subsequent annealing. This irradiation process induces the precipitation of not only magnetic spinel-type Fe-oxide nanoparticles but also Au nanoparticles inside the glasses, which shows localized surface plasmon resonance absorption at the wavelengths larger than 500 nm. As the annealing time and the temperature increases, the position of the LSPR peaks exhibits red shifts, which is due to the growth of Au nanoparticles. Faraday rotation angles as a function of wavelength were measured, and the difference spectra exhibit distinct positive peaks, indicating that the coupling between the LSPR due to the Au nanoparticles and the diamagnetism of the matrix glass is effective. To decrease the coupling with the diamagnetic glass, a two-step annealing process (at 450 °C for 90 min and at 550 °C for 30 min) was carried out after irradiation with fs-laser. The preliminary annealing at the lower temperature contributes to the precipitation of ferrimagnetic magnetite nanoparticles. Au nanoparticles were subsequently grown by annealing at 550 °C. In this case, effective coupling between the LSPR and ferrimagnetic nanoparticles has significantly suppressed the intensity of the positive peak in the Faraday spectra compared with the single annealing process.

Coercivity enhancement of FePt thin films coated with a monolayer array of γ-Fe2O3 nanoparticles

We report on a two-dimensional magnetic nanocomposite material consisting of a monolayer of ~11nm diameter colloidal γ-Fe2O3 nanoparticles arrayed by the Langmuir–Blodgett method over a ~3nm thin film of FePt deposited on a glass slide substrate, thus exploiting the advantages of both thin film fabrication and chemical synthesis. The FePt film was obtained by magnetron sputtering of a FePt target, followed by vacuum annealing at 600°C. FePt magnetic polarization perpendicular to the film plane was observed. The parallel to the plane hysteresis loops are dominated by the diamagnetic glass substrate. The perpendicular to the plane hysteresis loops are highly square with a coercivity of 4.87×106/4π (A/m), which upon deposition of the monolayer array of γ-Fe2O3 nanoparticles increases to 6.31×106/4π (A/m).

High Verdet constant Ga:S:La:O chalcogenide glasses for magneto-optical devices

The magneto-optical rotation at room temperature was mea- sured for three Ga:S:La:O chalcogenide glasses at several laser lines in the visible. The first sample was a binary system constituted by 70 mol % Ga2S3 and 30 mol % La2O3, whereas in the second and third ones the lanthanum oxide was partially substituted by lanthanum sulfide, keeping the amount of gallium sulfide fixed. A pulsed magnetic field between 50 and 80 kG was used for the Faraday rotation measurements. The Verdet constant for one of the ternary samples was found to be as high as 0.205 min G 21 cm 21 at 543 nm, indicating that these chalcogenide glasses are very promising for magneto-optical applications. The data for each sample were fitted using the expected analytical expression for the magneto-optical dispersion. Measurements of the refractive index of the glasses at 632.8 nm are also reported. Data on the magneto-optical properties of two high Verdet constant, heavy-metal oxide diamagnetic glasses are also included for comparison. © 1999 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(99)00102-6)

The Faraday effect in diamagnetic glasses

The wavelength dispersions of the Faraday effect in typical diamagnetic glasses, i.e., silica, borate, silicate, tellurite, lead-bismuth-gallate, and As2S3, have been examined. The Verdet constant of the glasses decreases with increasing wavelength in the longer wavelength region of the absorption edge of the glasses, while it increases with increasing optical bandgap of the glasses. These phenomena have been successfully explained based on the Becquerel theory. A guiding principle in designing a diamagnetic glass with a high Verdet constant is proposed.

Accurate magneto-optic sensitivity measurements of some diamagnetic glasses and ferrimagnetic bulk crystals using small applied AC magnetic fields

Many materials exhibit a relatively large Faraday effect. A plane polarized optical beam passing through these materials has its plane of polarization rotated by a measurable amount proportional to the applied magnetic field strength parallel to the propagation direction of the beam. Some of the most sensitive materials of this kind are diamagnetic glasses and ferrimagnetic crystals. We have made accurate measurements of the magneto-optic sensitivity of a variety of diamagnetic glasses and ferrimagnetic bulk optic crystals using small applied ac magnetic fields in contrast to the more common technique involving very strong applied dc magnetic fields.