Different Concentrations Of Tb Research Articles

Concentration-dependent luminescence characterization of terbium-doped strontium aluminate nanophosphors.

The present investigation describes the synthesis of luminescent terbium-doped strontium aluminate nanoparticles emitting bright green light, which were synthesized through a solid-state reaction method assisted by microwave radiation. Various samples containing different concentrations of Tb were synthesized, and an analysis of their structural and morphological features was conducted using powder x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The band gaps of the samples were determined utilizing the Kubelka-Munk method. The quenching mechanism observed was identified to be due to dipole-dipole interaction using the Dexter theory. The optimized sample with a terbium concentration of 4at.% has a luminescence lifetime of 1.05 ms with 20.62% quantum efficiency. The results of this study indicate that the terbium-doped strontium aluminate fluorescent nanoparticles exhibit promising potential for a wide range of applications, including bioimaging, sensing and solid-state lighting.

Effect of excitation and doping concentration on the emission color of a fluorophosphate glass doped with Tb3+ and Eu3+

We report in this work on the optical properties of a fluorophosphate glass system having the starting composition [60 (NaH2PO3, H2O) + 15 ZnO + 15 BaF2 + 10 WO3] prepared by the conventional melt-quenching procedure and doped with different concentrations of Tb3+ and Eu3+ ions. The XRD diffraction pattern has proved the amorphous nature of this glass system. The analysis of the optical spectra showed that Tb3+ ions may be excited by UV or blue light directly or through energy transfer from tungsten species, whereas Eu3+ ions may be excited by UV or blue radiations through charge transfer bands or sensitization by Tb3+ ions. We have shown that we can tune the color of the emitted light by changing either the doping concentration or the excitation wavelength. We have also seen that it is possible to tune the color of the emitted light by the same glass sample just by varying the excitation power, which is more convenient than modifying the doping concentration or the excitation wavelength and it may be important for the conception of solid-state lighting source.

Assessing the impact of terbium on Mytilus galloprovincialis: Metabolic and oxidative stress responses

The increasing demand for electric and electronic equipment has led to a rise in potentially hazardous electronic waste, including rare-earth elements (REEs), such as terbium (Tb), which have been already detected in aquatic systems. This study investigated the biochemical effects of anthropogenic Tb on mussels over a 28-day period. The mussels were exposed to different concentrations of Tb (0, 5, 10, 20, 40 μg/L), and biomarkers related to metabolism, oxidative stress, cellular damage, and neurotoxicity were evaluated. Bioaccumulation of Tb in the mussels' tissue increased with exposure concentrations, but the bioconcentration factor remained similar between treatments. Exposure to Tb enhanced glycogen consumption and decreased metabolic capacity which could be seen as a physiological adaptation to limit Tb accumulation. Antioxidant defenses and glutathione S-transferases showed a more complex dose-response, with enzymatic responses increasing until 10 μg/L but then returning to control levels at 20 μg/L. At 40 μg/L, enzymatic responses were also enhanced but to a lower extent than at 10 μg/L. The presence of Tb had clearly an inhibitory effect on biotransformation enzymes such as carboxylesterases in a dose-dependent manner. Likely, thanks to biochemical and physiological adaptations, no cellular damage or neurotoxicity was observed in any treatments, confirming the mussels' ability to tolerate Tb exposure. Nevertheless, prolonged exposure to these concentrations could lead to harmful consequences when facing other environmental stressors, such as misallocating energy resources for growth, reproduction, and defense mechanisms.

Tb3+ ion luminescence monitors β-dicalcium silicate mineralization conversion

Tb3+ doped β-dicalcium silicate (β-Ca2SiO4: Tb3+) phosphors with different concentrations of Tb3+ were successfully manufactured by the high-temperature solid-state method. The crystal structures, morphological, chemical composition, and optical performances of these before and after mineralization phosphors were investigated via X-ray diffraction, scanning electron microscopy, energy dispersives X-ray spectroscopy, as well as photoluminescence. The crystal structure of β-Ca2SiO4 can be stabilized by adding Tb3+ ions. Under 375 nm excitation wavelength, Tb3+ occurs on 5D4→7F5 transition, β-Ca2SiO4: Tb3+ phosphors exhibit intense green emission which is located at 543 nm. During the mineralization experiment, β-Ca2SiO4: Tb3+ phosphors showed good biological activity and were rapidly transformed into hydroxyapatite (HA), and its luminescence intensity attenuated synchronously. All results suggest that the mineralization process of β-Ca2SiO4: Tb3+ can be monitored by observing the change in luminescence intensity of Tb3+ ions.

The effect of Tb3+ on magneto-optical properties of GeO2-B2O3-Li2O-MgO glasses

In this work, the paramagnetic magneto-optical glasses with composition of GeO2-B2O3-Li2O-MgO (GBLM) doped with 20–40 mol%Tb3+ ions were prepared by the high temperature melting method, and the influence of different concentrations of Tb3+ ions on the structure, luminescence and magneto-optical properties of the GBLM glass were investigated. It is found that when the doping concentration of Tb2O3 is 40 mol%, the density and effective doping concentration of Tb3+ ion of the GBLM glass are 5.87 g/cm3 and 13.58 × 1021 /cm3. Importantly, GBLM glasses exhibit good magneto-optical properties. When the wavelength of incident light is 633 nm, the Verdet constant of GBLM magneto-optical glass doped with 40 mol%Tb2O3 can reach -158.56 rad/(T·m), -143.04 rad/(T·m) at 273.15 K and 298.15 K, respectively, which are better than that of Terbium Gallium Garnet Crystal (TGG, -134 rad/(T·m)). Additionally, due to the 5D4→7F5 energy level transition of Tb3+, GBLM glass has bright green light emission near 544 nm. All these results indicate that there are broad application prospect for GBLM magneto-optical glass in optical isolators.

Magneto-optical and luminescent properties of Tb3+ ions doped GBPZ magneto-optical glass

Paramagnetic GeO2-B2O3-P2O5-ZnO (GBPZ) magneto-optical glass doped with different concentration of Tb3+ ions (20–45 mol%) was successfully prepared by high-temperature melting quenching technology. The effects of different concentrations of Tb3+ ions on the structure, magneto-optical properties and luminescence properties of GBPZ glass system were studied. Through theoretical calculation, the effective doping concentration, molar volume, oxygen packing density and theoretical optical alkalinity of Tb3+ ions in the glass were obtained and analyzed the effect of these parameters on the Verdet constant. It is worth noting that the GBPZ glass samples exhibit excellent magneto-optical properties, especially the Verdet constant value of the glass sample with Tb3+ ions doping concentration of 45 mol% reaches -168.55 rad/(T·m) at the incident light wavelength of 633 nm, which is significantly higher than the Verdet constant (-134 rad/(T·m)) of the commercially available terbium gallium garnet crystal, and the strong green emission located at 544 nm observed from the sample will contribute to GBPZ magneto-optical glass in optical field of application.

Asparagine modified downconversion NaGdF4:Dy3+/Tb3+ nanophosphor for selective and sensitive detection of Cu(ii) ion

Pure NaGdF4, NaGdF4:Dy3+, and Dy3+/Tb3+ co-doped NaGdF4 nanoparticles with different concentrations of Tb3+ (ranging from 3 to 20 mol%) were prepared via hydrothermal method.

Luminescent and structural behaviour of Tb+3 ions doped TiO2 nanoparticles synthesized by facile sol-gel method

Terbium doped titania (Tb–TiO2) nanoparticles with different concentration of Tb+3 ions were synthesized by sol-gel method. The crystallite size of nanoparticles decreased with increasing the Tb+3 ions concentration suggesting the inhibition of growth of TiO2 nanoparticles while the phase of nanoparticles was not affected by doping of Tb+3 ions. A marginal red shift in absorption and a decrement in the band gap from ⁓3.18 eV–3.06 eV after doping of Tb+3 ions were observed. The radiative transitions of Tb+3 ions were observed at 489 nm, 542 nm, 495 nm, and 654 nm corresponding to 5D4-7F6, 5D4-7F5, 5D4-7F4, and 5D4-7F3 transitions respectively in PL spectra. The PL intensity of these transitions first increases and then decreases with increasing Tb+3 concentration. The enhancement in PL intensity is due to more Tb+3 ions, and further addition of Tb+3 ions leads to the cluster formation which results in the loss of PL intensity.

Ultra-stable Tb3+: CsPbI3 nanocrystal glasses for wide-range high-sensitivity optical temperature sensing

In this work, a series of perovskite nanocrystals glasses with different concentrations of Tb3+ doped CsPbI3, which have excellent characteristics in terms of water resistance and cyclic thermal stability, were prepared by melt quenching and in situ crystallization methods. With the introduction of Tb3+, the photoluminescence quantum yield of CsPbI3 was greatly improved. Considering that the two fluorescence peaks of Tb3+ and CsPbI3 at different positions respond differently to temperature stimuli, we studied the potential application of those glasses as optical temperature detection tools in the temperature range of 80−480 K. More importantly, the results showed higher sensitivity than other tools, with the maximum absolute and relative temperature sensitivities reaching as high as 0.034 K−1 and 1.78 % K-1, respectively. This work is expected to provide an effective method for the application of CsPbX3 in high-performance optical temperature sensing materials.

Study of radioluminescence in LiMgPO4 doped with Tb, B and Tm

Lithium magnesium phosphate (LiMgPO4, called LMP) crystals doped with different concentration of Tb, B and Tm were tested in regard to their radioluminescence emitted during irradiation. LMP crystals were grown with a micro-pulling down method as rods at IFJ PAN. The samples in the form of the thin slices were very sensitive to the ionizing radiation. Differently doped LMP samples were tested in a fiber optic measurement system (called PORTOS) which was constructed and adopted to the specific spectral properties of LMP. The LMP detector placed at the end of 15 m fiber connected to the PORTOS device was tested with gamma rays emitted from Co-60 Theratron 780E as well as with a Cs-137 source in a Laboratory for Calibration of Radiation Protection Instruments at IFJ PAN. RL signal was roughly proportional to the dose rates in the wide range of the dose rates. The highest RL signal was recorded for LMP crystals doped with 0.8 mol% of Tb as well as doped with 0.8 mol% Tm. The radioluminescence signal was discussed in regard to the thermoluminescence (TL) glow curves and optically stimulated luminescence (OSL) decay curves for 14 differently doped LMP crystals.

Scintillation and dosimetric properties of Tb-doped CaF2 translucent ceramics synthesized by the spark plasma sintering method

ABSTRACT CaF2 translucent ceramics with different concentrations of Tb were synthesized by the spark plasma sintering (SPS) method, and their photoluminescence, scintillation and dosimetric properties were characterized. The Tb-doped samples exhibited scintillation with several sharp peaks across the range from 365–630 nm due to 4 f-4 f transitions of Tb3+ and with a broad peak at approximately 300 nm due to self-trapped excitons. Among the sample investigated, the scintillation intensity in the 365–630 nm range was highest for the 0.5% Tb-doped sample. As a dosimetric property, the Tb-doped samples exhibited thermally-stimulated luminescence (TSL) with a glow peak at approximately 90°C, and with a TSL response in a linear relationship to the X-ray dose over the dose range from 0.001 to 1 mGy. Optically stimulated luminescence (OSL) due to the 4 f-4 f transitions of Tb3+ was detected in the Tb-doped samples, moreover and the lowest detectable limit of OSL was at most 100 mGy.

A rht‐Type Luminescent Zn (II)‐MOF Constructed by Triazine Hexacarboxylate Ligand: Tunable Luminescent Performance and White‐light Emission Regulation through doping Eu3+/Tb3+

White‐light emitting materials have become a hot research field of luminescent MOF (Metal–Organic Framework) because of its high practical application value. Herein, we successfully synthesized and characterized a rht‐type fluorescent MOF Zn‐TDPAT [H6TDPAT = 2,4,6‐tris(3,5‐dicarboxylphenylamino)‐1,3,5‐triazine] with a topology of (3, 24) connected nodes. A series of MOFs materials x%Tb + y%Eu@Zn‐TDPAT were prepared by incorporating different concentrations of green emission center Tb3+ and red emission center Eu3+ into the blue‐emitting Zn‐MOF. The luminescence properties of MOFs materials x%Tb + y%Eu@Zn‐TDPAT can be effectively adjusted by incorporating different concentrations of Tb3+ and Eu3+ and can obtain multi‐color luminescence properties from blue, blue‐green, green, yellow green, yellow, blue‐red, yellow‐red and white. According to trichromatic mechanism, by reasonably matching the intensity of blue light, green light and red light emitted by x%Tb + y%Eu@Zn‐TDPAT at 420, 543 and 616 nm, MOFs materials 0.75%Tb + 5%Eu@Zn‐TDPAT, 0.65%Tb + 5.5%Eu@Zn‐TDPAT and 0.5%Tb + 7.5%Eu@Zn‐TDPAT with white‐light emission are obtained. Their CIE coordinates are 0.3162, 0.3345 (0.3162, 0.3345), (0.3138, 0.3339) and (0.3329, 0.3222), respectively, which are very close to ideal white‐light emission (0.3333,0.3333).

Control of white light emission via co-doping of Dy3+ and Tb3+ ions in LiLuF4 single crystals under UV excitation

The lithium lutetium fluoride (LiLuF4) single crystals co-doped with fixed ~ 1.7 mol% Dy3+ and different concentrations of Tb3+ concentrations from 0 to 2.7 mol% were prepared by a Bridgman technique. Influence of Tb3+ ion concentration on the spectroscopic properties of Dy3+/Tb3+ co-doped LiLuF4 single crystal was explored with the help of optical absorption, luminescence, and decay curve. Dy3+ ion acts as a sensitizer for Tb3+ ion emission by the energy transfer process of Dy3+:4F9/2 + Tb3+:7F6 → Dy3+:6H15/2 + Tb3+:5D4 under excitation of UV lights. Moreover, a fitting of the emission decay curve at 575 nm by the Inokuti–Hirayama expression suggested that the dipole–dipole energy transfer from Dy3+ to Tb3+ was dominated. The characteristic emission colors of the prepared crystal were estimated. An ideal white light emission with chromaticity coordinates of (0.328, 0.334) could be obtained and the emission color adjusted from the white to green region by varying Tb3+ ion concentrations under the excitation of UV light. In addition, the temperature-dependent fluorescence suggests that the Dy3+/Tb3+ co-doped LiLuF4 single crystal shows an excellent thermal stability.

Structural and Spectroscopic Characterization of Tb3+‐Doped MgAl2O4 Spinel Ceramics Fabricated by Spark Plasma Sintering Technique

Spark plasma sintering (SPS) technique is successfully used for the preparation of magnesium aluminate spinel ceramics doped with different concentrations of Tb3+ ions. Structural, morphological, optical, and photoluminescence (PL) characterization are conducted. It is demonstrated that the redshift in the absorption spectra is possibly due to the energy gap between the valence and conduction bands reducing and the formation of a higher concentration of nonbridging oxygen with an increase in the concentrations of Tb3+ ions in MgAl2O4 ceramics. The PL spectrum excited by nitrogen laser consists of a broad emission band with a maximum at λem ≈ 400 nm and a series of emission bands in the 400–700 nm spectral range responsible for Tb3+ ions. In the “blue” spectral region, the complex host centers such as oxygen vacancies are recorded. An increase in the terbium ion concentration does not lead to the effect of concentration quenching. Luminescence decay kinetics analysis for all ceramics samples is performed. The effect of terbium oxide on the optical, PL properties and luminescence decay kinetics of MgAl2O4 ceramics is discussed.

Optimization of dispersed LaPO4:Tb nanosol and their photoluminescence properties

LaPO4:Tb nanophosphor with different concentrations of Tb3+ 0.05–0.15 mol % has been synthesized via sol-gel process. The synthesized nanophosphor was dried under 80 °C for 24 hrs. Dependent on the different concentration of Tb3+, the optimum concentration for the enhanced luminescence intensity was determined to be 0.15 mol %. The high luminescent nanophosphor with Tb3+ = 0.15 mol % was heat treated at 200–800 °C for 4 hrs. The nanophosphor heat-treated at 600–800 °C showed high photoluminescence (PL) property by monitoring at 254 nm excitation wavelength. The nanophosphor heat-treated at 200–400 °C is well crystalline in the hexagonal phase, but the crystal phase nature is shifted to monoclinic in case of the sample that heat treated above 400 °C. On the basis of weakly agglomerated nanoparticles, the nanophosphor was dispersed and converted into nanosol under controlled bead mill wet process. Based on particle size analyzer (PSA) the obtained nanosol median particle size (D50) was below 200 nm. Finally, the low PL properties of LaPO4:Tb nanosol with their characteristics green color emission was recovered after calcination at 650 °C under N2 atmosphere for 2 hrs. The crystallinity, morphology and particle size of the nanophosphors were investigated using X-ray diffraction (XRD), FE-SEM, and PSA. The nanosol with green color emission prepared in this work potentially meets their applications for security coatings.

Photoluminescence, scintillation and TSL properties of Tb-doped strontium aluminoborate glasses

We synthesized strontium aluminoborate glasses doped with different concentrations of Tb (0.1, 0.5, 1.0 and 5.0 mol.%) by the conventional melt-quenching technique, and investigated their photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties to develop phosphor materials for radiation dosimetric methods. The Tb-doped samples showed PL and scintillation with sharp peaks approximately at 485, 540, 545, 580 and 620 nm due to the 4f-4f transitions of Tb3+. The 1.0% Tb-doped sample exhibited the highest intensity in PL and scintillation among the samples investigated. In addition, the Tb-doped samples showed TSL with a main glow peak approximately at 75 °C measured after X-ray irradiation of 1000 mGy. The TSL intensity of the 0.1% Tb-doped sample was the highest, and the 0.1–1.0% Tb-doped samples showed TSL with a linear response feature over the dose range of 0.1–1000 mGy.

Sensitization of luminescence from Sm3+ ions in fluoride hosts K2YF5 and K2GdF5 by doping with Tb3+ions

Spectroscopic properties and energy transfer mechanisms for isostructural fluoride K2YF5 and K2GdF5 crystals singly and doubly doped with different concentrations of Tb3+ and Sm3+ ions have been investigated under excitation in the deep ultraviolet (DUV) and vacuum UV (VUV) spectral regions. In these hosts luminescence of Sm3+ ions is enhanced under DUV excitation by doping with Tb3+ ions, namely, the Sm3+ excitation spectra show additional intense excitation in the region of Tb3+ spin-allowed 4f – 5d transitions at 200–220 nm due to energy transfer from Tb3+ to Sm3+. The decay curves of Tb3+ ion luminescence have been measured at room temperature for the series of samples containing different concentration of Sm3+ and have been fitted by the Inokuti-Hirayama model. The results have revealed that the dipole-dipole interaction is the dominant interaction mechanism in the energy transfer process from Tb3+ to Sm3+ ions. The probability (WET) and the efficiency (EET) of energy transfer from Tb3+ to Sm3+ increase depending on the Sm3+ concentration in these crystals.

Scintillation and TSL properties of Tb-doped NaPO3-Al(PO3)3 glasses

We synthesized NaPO3-Al(PO3)3 glasses with different concentrations of Tb (0.3, 1.0, 3.0 and 10.0 mol%) by the conventional melt-quenching technique. After the synthesis, their photoluminescence (PL), scintillation and TSL properties were characterized systematically. All the glass samples showed intense PL and scintillation having a spectrum of sharp peaks at around 490, 540, 590 and 620 nm due to the 4f-4f transitions of Tb3+. The intensities of PL and scintillation were the highest for the 10.0% Tb-doped glass among the samples investigated. In thermally-stimulated luminescence (TSL), the intensity was the highest for the 1.0% Tb-doped sample. We also demonstrated dose response of TSL, and the 0.3% and 1.0% Tb-doped samples exhibited a linear response to X-ray dose over a dose range of 10–10000 mGy.

Luminescent properties of Tb3+- doped TeO2-WO3-GeO2 glasses for green laser applications

Different concentrations of Tb3+ -doped oxyfluoro tellurite (TWGTb) glasses were prepared by conventional melt quenching technique and characterized for green laser applications. The Judd-Ofelt theory was applied to evaluate various spectroscopic and radiative parameters. The TWGTb glasses exhibit 5D3 → 7F5-3 and 5D4 → 7F6-0 transitions when excited at 316 nm radiation. The variation of intensity of 5D4 → 7F5 (Green) and 5D3 → 7F4 (Blue) transitions and the green to blue (IG/IB) intensity ratios were studied as a function of Tb3+ ions concentration. The laser characteristic parameters such as effective bandwidth (Δλeff), stimulated emission cross-section (σe), gain bandwidth (σe × Δλeff) and optical gain (σe × τR) were determined using the three phenomenological Judd-Ofelt intensity parameters. The fluorescence decay profiles of 5D4 metastable level exhibit single-exponential nature for all the samples. Based on the experimental results we suggest that the 1.0 mol% of Tb3+ -doped TWGTb glass could be a suitable laser host material to emit intense green luminescence at 545 nm.

Preparation of CaB4O7 nanoparticles doped with different concentrations of Tb3+: Photoluminescence and thermoluminescence/optically stimulated luminescence study

Small sizes of CaB4O7 nanoparticles doped with different concentrations of Tb3+ were prepared by using solution combustion method and thermal annealing treatment. The prepared nanophosphors show highly crystalline monoclinic structures with particle size of about 40 nm. The surface morphology and molecular bonding structure were investigated using TEM images and FTIR spectra. The emission and excitation PL spectra revealed the successful incorporation Tb3+ into the CaB4O7 crystal lattice. Thermoluminescence (TL) and Optically stimulated luminescence (OSL) of the 6 Gy X-Ray irradiated CaB4O7:Tb sample are recorded and maximum intensity could be observed for 1at.wt% concentration of Tb. Kinetic parameters of the TL and OSL glow curves were evaluated using deconvolution and conventional fitting methods. Fading characteristics of the TL and OSL signals are recorded for the period of 40 days.