Doping Of Tb Research Articles

Electrospinning Preparation, Structure, and Properties of Fe3O4/Tb(acac)3phen/Polystyrene Bifunctional Microfibers.

Compared to single functional materials, multifunctional materials with magnetism and luminescence are more attractive and promising; Thus, it has become an important subject. In our work, bifunctional Fe3O4/Tb(acac)3phen/polystyrene) microfibers with magnetic and luminescent properties (acac: acetylacetone, phen: 1,10-phenanthroline) were synthesized by simple electrospinning process. The doping of Fe3O4 and Tb(acac)3phen made the fiber diameter larger. The surface of pure polystyrene microfibers and microfibers doped only with Fe3O4 nanoparticles were chapped similar to bark, whereas the surface of the microfibers was smoother after doping with Tb(acac)3phen complexes. The luminescent properties of the composite microfibers were systematically studied in contrast to pure Tb(acac)3phen complexes, including excitation and emission spectra, fluorescence dynamics, and the temperature dependence of intensity. Compared with the pure complexes, the thermal activation energy and thermal stability of composite microfiber was significantly improved, and the luminescence of the unit mass of Tb(acac)3phen complexes in composite microfibers was stronger than that in pure Tb(acac)3phen complexes. The magnetic properties of the composite microfibers were also investigated using hysteresis loops, and an interesting experimental phenomenon was found that the saturation magnetization of the composite microfibers gradually increased with the increase in the doping proportion of terbium complexes.

Post-synthetic Ln@modified MIL (Ti) framework in sono-photocatalysis degradation of carbaryl

Carbaryl is one of the most widely applicable pesticide to protect fruits, cereals and vegetables, however it is ascribed as one of human carcinogens by US Environmental Protection Agency. Hence, removal of carbaryl from water down to the permissible level is highly recommended. Therefore, the current study interested in the successful removal of carbaryl by catalytic degradation assisted by sonolysis and photolysis. Metal organic framework-based MIL-125-NH2 was synthesized and post modified with pyridine-2,6-dicarbonyl dichloride to produce PDC-MIL-125-NH2. Secondly, lanthanide (Ln) based Eu and Tb was doped in the PDC-MIL-125-NH2 to obtain Ln@PDC-MIL-125-NH2. The synthesized materials were characterized and confirmed by 1HNMR, FTIR, SEM, EDX and XRD. The all obtained materials were employed in the sonolysis, photolysis and sono-photolysis degradation of carbaryl. The results declared that the carbaryl degradation was followed the order of MIL-125-NH2 < PDC@MIL-125-NH2 < Tb@PDC@MIL-125-NH2 < Eu@PDC@MIL-125-NH2 < Eu/Tb@PDC@MIL-125-NH2. In case of Eu/Tb@PDC@MIL-125-NH2, the carbaryl degradation amounts (percentage) within 30 min were significantly enlarged from 304 mg/g (40.5%) for sonolysis to 630 mg/g (84%) for photolysis and to 749.7 mg/g (99.9%) for sono-photolysis. Doping of Eu and Tb within PDC@MIL-125-NH2 improved the catalytic degradation of carbaryl by factor of 2.1. After doping of Eu/Tb within PDC-MIL-125-NH2, the degradation rate in sono-photolysis was accelerated by factor of 2.6. The catalytic degradation of carbaryl was significantly enhanced by applying of sono-photolysis and by immobilization of Ln within PDC-MIL-125-NH2 catalyst. After 6 repetitive sono-photolysis degradation cycles, the degradation percentage of carbaryl was lowered from 99.9% to 92.4% only.

Antiferromagnetic topological insulating state in Tb0.02Bi1.08Sb0.9Te2S single crystals

Topological insulators are emerging materials with insulating bulk and symmetry protected nontrivial surface states. One of the most fascinating transport behaviors in a topological insulator is the quantized anomalous Hall insulator, which has been observed in magnetic-topological-insulator-based devices. In this work, we report a successful doping of rare earth element Tb into ${\mathrm{Bi}}_{1.08}{\mathrm{Sb}}_{0.9}{\mathrm{Te}}_{2}\mathrm{S}$ topological insulator single crystals, in which the Tb moments are antiferromagnetically ordered below $\ensuremath{\sim}10$ K. Benefiting from the in-bulk-gap Fermi level, transport behavior dominant by the topological surface states is observed below $\ensuremath{\sim}150$ K. At low temperatures, strong Shubnikov--de Haas oscillations are observed, which exhibit 2D-like behavior. The topological insulator with long range magnetic ordering in rare earth doped ${\mathrm{Bi}}_{1.08}{\mathrm{Sb}}_{0.9}{\mathrm{Te}}_{2}\mathrm{S}$ single crystal provides an ideal platform for quantum transport studies and potential applications.

Synthesis, and photoluminescence and magnetic properties of Tb-doped AlN single-crystalline nanobelts

Tb doped AlN (AlN:Tb) nanobelts were prepared by in situ doping of Tb using a plasma-assisted arc discharge method. The structure, composition and morphology of the doped nanobelts were studied by means of X-ray diffraction, scanning and transmission electron microscopy and X-ray photoelectron spectroscopy, revealing that Tb ions have been introduced into the lattice of wurtzite-structured AlN nanobelts. The AlN:Tb nanobelts exhibit distinct emission peaks corresponding to intra-4f electron transitions of Tb3+ ions, and room temperature ferromagnetism, which make AlN:Tb nanobelts an excellent candidate for applications in future solid light-emitting diodes and spintronic nanodevices.

Influence of rare earth element terbium doping on microstructure and magnetostrictive properties of Fe81Al19 alloy

Fe81Al19Tbx (x=0, 0.05, 0.1, 0.2, 0.3, 0.4) alloys were prepared by a non-consumable vacuum arc melting technique under an inert argon gas atmosphere. The microstructures of the alloys were studied by X-ray diffraction (XRD) and scanning electron microscopy combined with an energy dispersive spectroscopy (SEM/EDS). The magnetic properties and magnetostriction coefficients of the alloys were measured by a vibrating sample magnetometer (VSM) and adifferential resistive strain sensor, respectively. The results show that the Fe81Al19 alloy consists of a single A2 phase with bcc structure, whereas the Tb doped Fe81Al19 alloys are composed of the A2 phase and a small amount of rare earth-rich phase. The doping of the rare earth element Tb makes the Fe81Al19 alloy preferentially oriented along with the <100> crystal direction. With the increase of Tb content, the magnetostriction coefficient of the alloy first increases and then decreases. When x=0.1, the magnetostriction coefficient reaches the maximum, which is 146 × 10−6. Compared with the as-cast Fe81Al19 alloy (27 × 10−6), it increases by 441%. The enhanced magnetostrictive properties are mainly attributed to the preferred orientation along <100> of A2 phase of the Tb doped Fe81Al19 alloys and lattice distortion caused by the small amount of rare earth atoms entering the Fe–Al alloy lattice.

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.

Near infrared reflective pigments based on Bi3YO6 for heat insulation

In this paper, a series of high performance near-infrared reflective pigments based on Bi3YO6 doped with Fe2O3 and Tb4O7 were prepared by high-temperature calcination method. The pigments were characterized by some analytic techniques, such as XRD, Particle size analyzer, SEM, EDS, UV–vis–NIR spectrophotometer, CIE L*a*b* (1976) color space and infrared thermal imaging. Experimental results showed that the Fe2O3 doping in Bi3YO6 could change the color from bright yellow to ochre red. The substitution of Tb (IV)-doped pigments changed the color to dark orange. The doping of Fe (III) and Tb (IV) contributed to enriching the color diversities of pigments. Among the synthesized pigments, Bi3-xFexYO6 and Bi3Y1-xTbxO6+δ displayed a disordered defective fluorite-type structure. The effect of doping Fe (III) and Tb (IV) reduced the near-infrared reflectance of the pigment. Excepting for Bi3-xFexYO6 (x = 0.8), the near infrared reflectance of some other pigments were higher than the China National standard (CNs). Chemical resistance tests showed that the pigments had excellent acid and alkali resistance. Finally, the application practical of traditional iron oxide yellow pigment and three prepared pigments, i.e., Bi3YO6, Bi3-xFexYO6 (x = 0.4) and Bi3Y1-xTbxO6+δ (x = 0.05) were studied and compared by infrared thermal imaging. The test results showed that Bi3YO6 still had a strong near-infrared reflection effect after being painted. Compared with traditional iron yellow pigment, Bi3YO6 could reduce the surface temperature of galvanized sheet by 20 °C under the illumination of infrared light. The series of Fe (III) and Tb (IV) doped pigments prepared in this paper have revealed some promising application values.

A method to visually observe the degradation-diffusion-reconstruction behavior of hydroxyapatite in the bone repair process

Nanostructured hydroxyapatite (HAp) has been applied widely as a scaffold material for bone tissue engineering for its good osteoinduction and biodegradability. However, the degradation process and the distribution of degraded HAp within the bone-defect cavity is still not clear. To visually study the behavior of HAp in bone repair process, a membrane of HAp/terbium (Tb)-HAp nanowires (NWs) was prepared with a concentric circle structure (CCS), of which the inner circle and the outer ring were constructed with Tb-HAp and HAp NWs, respectively. HAp/Tb-HAp CCS membrane possessed good osteogenic capacity and efficient fluorescence in the center for visualization. The in vitro experimental results proved that the Tb-HAp and HAp NWs membranes both presented high cytocompatibility and adequate efficiency to induce osteogenic differentiation of bone marrow stem cells (BMSCs). HAp/Tb-HAp CCS membranes were then implanted into a rat calvarial bone-defect model to study the behavior of HAp in bone repair process in vivo by tracking the fluorescence distribution. The results showed that the fluorescence of Tb-HAp diffused gradually from the inner circle to the outer ring, which suggested that the HAp was first degraded, and then the degraded product was diffused and finally reconstructed. Further, the histological results proved that the doping of Tb did not impair the promotive effect of HAp on bone repair process. Therefore, this study provided a visual method to observe the degradation-diffusion-reconstruction behavior of HAp nanomaterials in bone repair process. Statement of significanceThe study of dynamic degradation process of implanted hydroxyapatite (HAp) materials in bone-defect cavity is of great significance to bone tissue engineering applications. Here, we designed a HAp/Tb-HAp nanowires (NWs) membrane with concentric circle structure (CCS) to visibly observe the behavior of HAp during bone repair process. HAp/Tb-HAp CCS membrane possessed both osteoinduction ability and fluorescence property. Calvarial bone-defect repair experiments in vivo showed that the fluorescence of Tb-HAp diffused gradually from inner circle to outer ring, which suggested that HAp was first degraded, then diffused and finally reconstructed. Therefore, this invention provides not only a visible method to observe the degradation-diffusion-reconstruction behavior of HAp-based biomaterials, but also a basic understanding of the dynamic change of HAp-based biomaterials.

The impedance, dielectric and piezoelectric properties of Tb4O7 and Tm2O3 doped KNN ceramics

Rare earth (RE) elements (Tb, Tm) doped K0.5Na0.5NbO3 (KNN) lead-free ceramics were fabricated using conventional solid-state reaction method. All samples with dominating orthorhombic phase are well developed. The effects of Tb and Tm on impedance, dielectric and ferroelectric properties are systematically studied. There are relaxation-like features of the ceramics after the doping of RE elements. Conduction processes were affected by defect, especially in KNN-Tb ceramics, in the higher temperature region. The doping of Tb and Tm increases density, remnant polarization and the piezoelectric constant of the KNN ceramics due to the effect of donor doping. The overall analysis has confirmed the significance of RE elements (Tb, Tm) doping in KNN and shows that it is a promising candidate as lead-free piezoelectric ceramics.

P‐187: Electronic Structures of Various Color Light‐Emitting Amorphous Oxide Semiconductor Thin Films

We report multi‐color semiconductor phosphor thin films based on amorphous Ga2Ox semiconductor (a‐Ga2Ox), which improved quantum efficiency compared to already‐reported a‐IGZO:Eu. Doping of Eu, Sm, Pr, Dy and Tb emitted different visible colors such as red, yellow, and green. Photoemission spectroscopy revealed their electronic structures and light‐emission mechanisms.

Structural, spectral, dielectric and magnetic properties of Tb–Dy doped Li-Ni nano-ferrites synthesized via micro-emulsion route

Terbium (Tb) and dysprosium (Dy) doped lithium-nickel nano-sized ferrites (Li0.2Ni0.8Tb0.5xDy0.5xFe2−xO4 where x=0.00−0.08) were prepared by micro-emulsion technique. The X-ray diffraction (XRD) patterns confirmed the single phase cubic spinel structure. The lattice constant was increased due to larger ionic radii of Tb3+ and Dy3+ cations. The crystallite size was found in the range 30–42nm. The FTIR (Fourier transform infrared spectroscopy) spectra revealed two significant absorption bands (~400–600cm−1) which indicate the formation of cubic spinel structure. The peaking behavior of dielectric parameters was observed beyond 1.5GHz. The dielectric constant and dielectric loss were found to decrease by the increase of Tb–Dy contents and frequency. The doping of Tb and Dy in Li–Ni ferrites led to increase the coercive field (120–156Oe). The smaller magnetic and dielectric parameters suggested the possible utility of these nano-materials in switching and microwave devices applications.

White-light emitting materials with tunable luminescence based on steady Eu(iii) doping of Tb(iii) metal–organic frameworks

White-light emission materials were successfully acquired based on a sequence of isostructural co-doped lanthanide coordination polymers [EuxTb1−x(Hbtca)(phen)] (0 ≤ x ≤ 1).

A Strategy to enhance Eu3+ emission from LiYF4:Eu nanophosphors and green-to-orange multicolor tunable, transparent nanophosphor-polymer composites.

LiYF4:Eu nanophosphors with a single tetragonal phase are synthesized, and various strategies to enhance the Eu3+ emission from the nanophosphors are investigated. The optimized Eu3+ concentration is 35 mol%, and the red emission peaks due to the 5D0 →7FJ (J = 1 and 2) transitions of Eu3+ ions are further enhanced by energy transfer from a sensitizer pair of Ce3+ and Tb3+. The triple doping of Ce, Tb, and Eu into the LiYF4 host more effectively enhances the Eu3+ emission than the core/shell strategies of LiYF4:Eu(35%)/LiYF4:Ce(15%), Tb(15%) and LiYF4:Ce(15%), Tb(15%)/LiYF4:Eu(35%) architectures. Efficient energy transfer from Ce3+ to Eu3+ through Tb3+ results in three times higher Eu3+ emission intensity from LiYF4:Ce(15%), Tb(15%), Eu(1%) nanophosphors compared with LiYF4:Eu(35%), which contains the optimized Eu3+ concentration. Owing to the energy transfer of Ce3+ → Tb3+ and Ce3+ → Tb3+ → Eu3+, intense green and red emission peaks are observed from LiYF4:Ce(13%), Tb(14%), Eu(1-5%) (LiYF4:Ce, Tb, Eu) nanophosphors, and the intensity ratio of green to red emission is controlled by adjusting the Eu3+ concentration. With increasing Eu3+ concentration, the LiYF4:Ce, Tb, Eu nanophosphors exhibit multicolor emission from green to orange. In addition, the successful incorporation of LiYF4:Ce, Tb, Eu nanophosphors into polydimethylsiloxane (PDMS) facilitates the preparation of highly transparent nanophosphor-PDMS composites that present excellent multicolor tunability.

Synthesis of Novel Nontoxic Yellow Pigments: Sr2Ce1−xTbxO4

Abstract Novel yellow inorganic pigments Sr2Ce1−xTbxO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by the conventional solid-state route. The structure and morphology of the developed pigments were characterized using powder X-ray diffractometer (XRD) and scanning electron microscope (SEM), respectively. A UV–vis–NIR spectrophotometer was employed to investigate the optical properties, and the color characteristics were evaluated by CIE 1976 L*a*b* color scales. The Tb substitution extends the absorption edge to longer wavelengths by introducing an additional electronic level between the valence and conduction bands. Consequently, the prepared pigments exhibit various yellow colors by fine tuning of the band gap from 3.03 (white) to 2.52 eV (reddish-greenish yellow). Doping of Tb into Sr2CeO4 enhances the NIR reflectance at 1100 nm from 87% to 91%. The coloring performance of the synthesized pigments was investigated in the polymer matrix for plastic coloring applications. The exhibition of high NIR reflectance with comparable color properties of these pigments makes them potential candidates as cool colorants to reduce the heat build-up.

Growth and luminescence of Tb-doped ZnO nanocones

In this paper, Tb-doped ZnO nanocones are fabricated on silicon substrates using the high-temperature and high-pressure pulsed-laser deposition. Tb-doped ZnO nanocones are agave-like and the bottoms of nanocones huddle together. The luminescence properties of Tb-doped ZnO nanocones are characterized. Two peaks at about 543 and 586nm are identified to be from the doped Tb3+ ions in cathodoluminescence spectrum of sample. It can be concluded that the doping of Tb plays an important role in improve the luminescence property of ZnO nanostructures. The growth mechanism of ZnO nanocones can be explained by vapor–liquid–solid process. The doping of Tb ions in ZnO nanocones is dominated by surface diffusion.

Multiferroic properties of Tb-doped BiFeO3 nanowires

Nanoscale, multifunctional, multiferroic materials possess strong magnetoelectric coupling (ME), open exciting multitudinous ways for designing future nanoelectronic and spintronic device applications. Bulk nanowires (100 nm), pure, and Tb-doped BiFeO3 multiferroic nanowires (20 nm) have been synthesized by colloidal dispersion template-assisted technique. The effects of Tb-doping and size of synthesized nanowires on structural, electrical, magnetic, dielectric, and magnetodielectric properties have been investigated. X-ray diffraction study reveals that doping of Tb in BiFeO3 nanowires leads to structural transformation from rhombohedral to orthorhombic. X-ray photoemission analysis confirms the +3 oxidation state of Fe and high purity of samples. Bulk nanowires exhibit antiferromagnetic characteristics, whereas the Tb-doped BiFeO3 nanowires show ferromagnetic character. Moreover, with increase in Tb concentration, the saturation magnetization increases. Temperature-dependent magnetization study suggests their size-dependent ferro and ferri-magnetic behavior. Polarization versus electric field (P–E) study reveals that pure BiFeO3 nanowires possess elliptical loop; however, doping of Tb results in rectangular loop— portentous good ferroelectric properties. All synthesized samples exhibit frequency-dependent dielectric constant which decreases with increase in frequency and remains fairly constant at higher frequencies. Leakage current density decreases with increase in Tb concentration, and has been found to be three orders of magnitude less than those of bulk BiFeO3 nanowires. The ME coupling in synthesized nanowires was estimated by measuring magnetodielectric. A very high value of ME, 7.2 %, has been found for 15 % Tb-doped BiFeO3 nanowires. In this communication, we, for the first time, report new cue on size-dependent Tb-doped BiFeO3 nanowires, which may be further used to explore its technological device applications.

セリア－ジルコニア－テルビア系固溶体の合成と分光特性評価

Ceria-zirconia-terbia solid solutions were synthesized by co-precipitation method. The powders were characterized by XRD, colorimetric assessment and UV-Vis diffuse reflectance. A solid solution phase structure was obtained for all of the samples heated at 900°C and belongs to cubic fluorite structure or distorted fluorite structure. It was found that the lattice size decreased with increasing Zr content in the range x = 0 to 0.8 in ZrxCe1-xO2 and ZrxCe0.99-xTb0.01O2-δ. Diffuse reflectance spectra of the ZrxCe1-xO2 solid solutions in the UV region showed the broad shoulder-type band at 320-350 nm, which was assigned to interband transitions in CeO2 and additionally broader band in higher wave length region in solid solution. It was observed that ZrxCe1-xO2 powder became deeper yellow depending on Zr content, and that the doping of Tb resulted in warm colour in CeO2-ZrO2 based solid solution. The powders in the system of ZrxCe1-xO2 and ZrxCe0.99-xTb0.01O2-δ were possible pigments with environmental friendly properties toward future ceramic application.

Host Sensitization of Tb3+ Ions in Tribarium Lanthanide Borates Ba3Ln (BO3)3 (Ln = Lu and Gd)

The vacuum-ultraviolet (VUV) spectroscopic properties of undoped and Tb(3+)-doped borates Ba(3)Ln(BO(3))(3) (Ln = Lu and Gd) with different crystal structures were investigated by using synchrotron radiation. Ba(3)Lu(BO(3))(3) (BLB) crystallizes in a hexagonal structure, whereas Ba(3)Gd(BO(3))(3) (BGB) crystallizes in a trigonal structure. The maximum host absorption for BLB and BGB was found to locate at ~179 and ~195 nm, respectively. Upon host excitation, BLB exhibits an intrinsic broad UV emission centered at 339 nm, which is attributed to the recombination of self-trapped excitons that may presumably be associated with band-gap excitations or molecular transitions within the BO(3)(3-) group. In contrast to BLB, no broad emission but line emission ascribed to a Gd(3+)(6)P(J)-(8)S(7/2) transition was observed in the emission spectrum of BGB. Upon doping of Tb(3+) ions into the hosts of BLB and BGB, an efficient energy transfer from the host excitations to Tb(3+) via host/Gd(3+) emission was observed, showing that host sensitization of Tb(3+) occurs in these rare-earth borates.

LaAlO3 Hollow Spheres: Synthesis and Luminescence Properties

Nearly monodisperse LaAlO(3) hollow spheres are synthesized by a novel precursor thermal decomposition method. Spherical colloids of capsulelike precursors with uniform diameters of 273 ± 35 nm have been synthesized by a solvothermal method. These spherical colloids could convert to LaAlO(3) hollow spheres with diameters of 166 ± 26 nm by a thermal decomposition process. The thermal transformation process from the precursors to LaAlO(3) was characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and the Fourier transform infrared spectroscopy (FT-IR). By the doping of various lanthanide ions (Sm(3+), Eu(3+), and Tb(3+)), the emission luminescence of lanthanide-doped LaAlO(3) hollow microspheres can be tuned from red to green. In particular, these luminescent LaAlO(3) hollow spheres can be well dispersed in polar solvents such as the ethanol and water, which broadens the range of potential applications of these hollow spheres. The UV-vis absorption spectra show energy absorption at 211, 223, and 313 nm corresponding to the host lattice absorption and charge-transfer transitions. The results are in good agreement with the peaks observed in the excitation spectra.

Synthesies and properties of Tb-doped GaN nanowires

The synthesis of Tb-doped GaN nanowires on Si (111) substrates through ammoniating Ga2O3 films doped with Tb was investigated. X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy and photoluminescence were used to characterize the composition, structure, morphology and optical properties of the products. The results show that the as-synthesized GaN nanowires doped with 3 at % Tb are of single-crystalline hexagonal wurtzite structure. The nanowires have diameters ranging from 30 to 50 nm and the lengths up to tens of micrometers. An f-f intra-atomic transition of rare earth at 545 nm corresponding to 5D4–7F5 of the Tb3+ and other two peaks related with doping are observed in PL spectrum, confirming the doping of Tb into GaN. The growth mechanism of GaN nanowires was discussed briefly.