Concentration dependent structural, thermal, and optical features of Pr 3+-doped multicomponent tellurite glasses

Tuning the structural, thermal, and optical properties of low phonon energy glasses such as tellurite glasses (phonon energy ∼750 cm−1) with suitable rare earth dopants is a key issue in the fabrication of solid state lasers and optical amplifiers. In this work, (70-x) TeO2-10 WO3-10 ZnO-5 TiO2-5 Na2O-(x) Pr2O3 (x = 1.0–5.0 mol %) glasses were synthesized with high optical quality and characterized using X-ray diffraction (XRD), Scanning electron microscopy and Energy dispersive X-ray analysis (SEM-EDAX), Attenuated total reflectance-Fourier transform infrared (ATR-FTIR), Raman spectroscopy, Thermo-gravimetric analysis (TGA), Differential scanning calorimetry (DSC), optical absorption and luminescence techniques. The XRD and SEM measurements reveal the amorphous nature of all the prepared glasses and EDAX confirms all the elements present in the respective glasses. The presence of various functional groups such as stretching vibrations of Te[single bond]–O bonds in the [TeO4] trigonal bi-pyramid units, symmetrical stretching or bending vibrations of Te[single bond]–O[single bond]–Te or O[single bond]–Te[single bond]–O linkages at corner sharing sites along the chains of TeO4, TeO3 and TeO3+1, stretching vibrations of W[single bond]–O– and W[double bond; length as m-dash]═O bonds in WO4 tetragonal or WO6 octagonal units, vibrations of Zn[single bond]–O bonds from ZnO4 groups, including non-hygroscopic nature of the glasses are confirmed by ATR-FTIR and Raman spectra, respectively. For Pr3+-doped glasses, from the DSC profiles the glass transition temperature (Tg), onset crystallization temperature (Tx), crystallization temperature (Tc), and melting temperature (Tm) are identified and the evaluated thermal stability values varied in the temperature range of 169–220 °C with increasing Pr3+ doping concentration. Further, the Pr3+ -doped tellurite glasses demonstrate excellent glass stability with higher criterion of Hruby's value (HR) between 1.9 and 3.9. From the measured optical absorption spectrum, experimental oscillator strengths are calculated and used to evaluate three phenomenological Judd-Ofelt (J-O) intensity parameters Ω_λ_ (_λ_ = 2, 4 and 6) and respective radiative properties such as radiative transition probabilities (AR), the branching ratios (βR), and the radiative lifetime (τR) of metastable states for 1.0 mol % Pr3+-doped glass. Five main emission transitions at 3P0 → 3H5 (530 nm; green) with a shoulder at 543 nm, a weak band at 1D2 → 3H4 (592 nm; orange), 3P0 → 3H6 (615 nm; orange), 3P0 → 3F2 (649 nm; red), and 3P0 → 3F3 (686 nm; red) upon exciting at 486 nm (3H4 → 3P0) wavelength are observed from the luminescence spectra of Pr3+-doped tellurite glasses. Following the energy level diagram, Pr3+ ion concentration quenching on the luminescence intensity has been explained by a non-radiative energy transfer between the ions through cross-relaxation and energy migration processes. The concentration dependent structural, thermal, and optical behaviors of Pr 3+-doped tellurite glasses are understood and our systematic analysis could contribute towards the development of suitable optical devices fabrication. Raman spectra of all the synthesized glasses

Structural and optical characteristics of erbium doped ternary TeO2-TiO2-Bi2O3 glasses

In this work we investigated both structural and optical characteristic of erbium doped ternary TeO2-TiO2-Bi2O3 tellurite oxide based glasses, synthesized via melt-quench method. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed its glassy nature and stability. Raman analysis revealed the presence of various coordination state TeO2 network consisting stretching/bending vibrations of Te-O bonds in the [TeO4] trigonal bi-pyramid units and fraction of [TeO3, TeO3+1] trigonal pyramids. From optical absorption measurement both optical band gap and Judd-Ofelt analysis (intensity parameters Ωt (t=2, 4, 6), transition probabilities, and radiative lifetimes of the Er3+ ions) have been performed for both host and doped glasses respectively. Photoluminescence studies for upconversion and near-infrared emissions analysis (under 980 nm excitation at room temperature. Both optical transition mechanism which involved nonradiative energy transfer between Er3+ ions through cross-relaxation and energy migration were also explained in detailed

Acaricidal activity of Foeniculum vulgare against Rhipicephalus annulatus is mainly dependent on its constituent from trans-anethone

Globally, the economic losses due to hard ticks infestation and the control of the associated diseases have been calculated at USD $13.9-18.7 billion per year. The economic impact is related to its direct damage to the skins, blood loss, anemia, severe immunological reactions and indirect losses that related to the effects of hemoparasites, cost of treatment for clinical cases and expenses incurred in the control of ticks. The current study evaluated the acaricidal activities of fennel Foeniculum vulgare essential oil and its main components; trans-anethole and fenchone; against R. annulatus. GC-MS analysis revealed that this oil contained 16 components representing 99.9% of the total identified compounds with E-anethole being the predominant component(64.29%), followed by fenchone (9.94%). The fennel oil and trans-anethole showed significant acaricidal activities. The LC50 of the fennel oil was attained at concentrations of 12.96% for adult ticks and 1.75% for tick larvae meanwhile the LC50 of trans-anethole was reached at concentrations of 2.36% for adult tick and 0.56% for tick larvae. On the contrary, fenchone showed no any significant adulticidal activities and its LC50 attained at a concentration of 9.11% for tick larvae. Regarding repellence activities, trans-anethole achieved 100% repellency at the concentration of 10% while fennel showed 86% repellency at the same concentration. Fenchone showed no repellency effect. Treatment of larvae with fennel, trans-anethole, and fenchone LC50 concentrations significantly inhibited the acetylcholinesterase activity. Meanwhile, glutathione s-transferase activity was significantly decreased in fennel treated larvae but no significant effect was found in the larvae of trans-anethole and fenchone groups. These results indicate that the acaricide effect of fennel oil may attributed to its high content of trans-anethole. This was supported by potent adulticidal, larvicidal, and repellency effects of trans-anethole against Rhipeciphalus annulatus tick and therefore it could be included in the list of acaricide of plant origin

Structural, thermal and optical studies of bismuth doped multicomponent tellurite glass

In this communication, structural, thermal and optical absorption properties of bismuth doped multicomponent tellurite glass (69TeO2-10ZnO-10WO3-5Na2O-5TiO2-1.0Bi2O3 (mol %)) synthesized using melt quench method is reported. The X-ray diffraction confirms the amorphous structure of the synthesized glass. IR spectrum of bismuth doped glass show band at 601 cm-1. Raman analysis observed mainly in four spectral regions which are R1 (65-150) cm-1, R2 (280-550) cm-1, R3 (880-950) cm-1 and R4 (916-926) cm-1 and identified bands are assigned to respective molecular groups. Thermogravimetric analysis profile show stability regarding to weight loss. Differential scanning calorimetry indicates good thermal stability of the synthesized glass for its applications in optical fibers. The absorption spectrum identified the cutoff wavelength at 430 nm

Acaricidal activity of tea tree and lemon oil nanoemulsions against Rhipicephalus annulatus

Tick infestation is a serious problem in many countries since it has an impact on the health of animals used for food production and pets, and frequently affects humans. Therefore, the present study aimed to investigate the acaricidal effects of nanoemulsions of essential oils o

Structural, thermal, and optical analysis of zinc boro-aluminosilicate glasses containing different alkali and alkaline modifier ions

In this article, structural, thermal, and optical properties of zinc boro-aluminosilicate glasses with addition of different alkali (Li, Na, and K) and alkaline oxides (Mg, Ca, Sr, and Ba) have been reported. 10 mol% of alkali and alkaline oxides were incorporated into Zinc boro-aluminosilicate glasses and all these glasses possess high optical quality. Samples were characterized using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDAX), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), and optical absorption spectroscopy. The XRD and SEM measurements demonstrated the amorphous origin for all the prepared glasses and EDAX confirms that all the elements are presented in the prepared glasses. The presence of various functional groups such as triangular and tetrahedral-borate (BO3 and BO4) was confirmed by ATR-FTIR and Raman spectra, and both of the ATR-FTIR and Raman spectra show lower phonon energy for H3 (K2O) in alkali series, and H7 (BaO) for alkaline. From TGA analysis we found a lower weight loss < 0.1% in K2O, MgO, and BaO; and from the DSC profiles the glass transition temperature (Tg), onset crystallization temperature (Tx), crystallization temperature (Tc), and melting temperature (Tm) were identified and related different thermal parameters are evaluated. Alkali and alkaline influenced Zinc boro-aluminosilicate glasses demonstrate excellent glass stability. From the optical absorption spectra, we calculated cut-off wavelength and it shows spectral shifting to longer wavelength with alkali (Li → Na → K), and alkaline (Mg → Ca → Sr → Ba) modifiers. We investigated optical band gap energy also for allowed transitions in UV–visible region using three methods; direct, indirect, and absorption spectrum fitting (ASF)

Structural, thermal, optical and dielectric studies of Dy3+: B2O3-ZnO-PbO-Na2O-CaO glasses for white LEDs application

Dy3+-doped borate glasses with nominal composition (60-x) B2O3-10 ZnO-10 PbO-10 Na2O-10 CaO-(x) Dy2O3 (x = 0, 0.1, 0.2, 0.5, 0.75, 1.0, 1.5 and 2.0 mol%) were prepared by the melt quenching technique. The XRD and SEM confirm the amorphous nature of the glasses and through EDAX, all the related elements were found in the synthesized glasses. The vibrations of metal cations such as Pb2+ and Zn2+, B–O–B bond bending vibrations from pentaborate groups, bending vibrations of BO3 triangles, and stretching vibrations of tetrahedral BO4− units etc. are identified from the respective FTIR and Raman spectra including the non-hygroscopic nature of the synthesized glasses. The TGA and DSC measurements were performed to study thermal properties, where ΔT >100 °C (ΔT = Tx – Tg) for all the glasses. Among all the Dy3+-doped glasses, the 0.75 mol% Dy3+-doped glass shows the highest PL intensity with four emissions, where the two transitions corresponding to 4F9/2 → 6H15/2 (blue) and 4F9/2 → 6H13/2 (yellow) are observed more intense than the others. The CIE chromaticity (x,y) coordinates for BZPNCDy 0.1 mol% glass are (0.398, 0.430), close to the white light region in the CIE 1931 chromaticity diagram. The dielectric properties of the 0.75 mol% Dy3+-doped glass such as dielectric constant, dielectric loss and AC conductivity were studied in the various frequencies and temperature

Novel Tellurite Glass (60-x)TeO2–10GeO2 -20ZnO–10BaO - xBi2O3 for Radiation Shielding

In this article, high dense glasses based heavy metal former and modifier have been synthesized. The glass system with composition formula of (60-x)TeO2–10GeO2 -20ZnO–10BaO - xBi2O3 (where x = 2.5, 5, 7.5, and 10 mol. %). The glasses have been produced using the usual melt, quenching, and annealing process. Many physical features were investigated. To confirm the amorphous nature of theses glasses, we examined the samples with X-ray diffraction in the range of between 10° and 80°. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) transmission spectrum for the current glass samples within the range of 400–1500 cm−1 has been recorded to study the behavior of the obtained glasses that is mixed between tellurium and germanium glass phase. To study the transparency and cut-off wavelength and other optical properties, Ultraviolet–Visible spectrometer (UV–Vis) was utilized between 200 and 800 nm. Radiation shielding ability of the (60-x) TeO2–10GeO2-20ZnO–10BaO-xBi2O3 glasses was examined. Monte Carlo simulation method was applied to estimate the shielding parameters for gamma photons with various energies varied in rang from 0.015 to 15 MeV. © 2020 Elsevier B.V.All Authors present their grateful acknowledge to the Universiti Putra Malaysia (UPM), for supporting this work by chemicals and services, which granted by UPM under IPB-9554200

Germanate Oxide Impacts on the Optical and Gamma Radiation Shielding Properties of TeO2-ZnO-Li2O Glass System

In this work, a series of tellurite glass combined with various concentrations of germanium oxide was fabricated according to the formula of (70-x)TeO2-xGeO2–20ZnO-10Li2O where x = 5, 10, 15 and 20 mol% via utilizing the melt-quench method for possible use in a radiation shielding applications. X-ray diffraction and Attenuated Total Reflectance Fourier Transform Infrared was employed to investigate the structure of the synthesized glasses. The density and Poisson's ratio for current samples reduced gradually from 5.221–5.008 g.cm−3 and 0.134–0.131, respectively, while the enhancement in bandgap values from 3.700–3.872 eV with addition of GeO2 is observed. The linear attenuation coefficient values at 0.015 MeV are 230.123 and 236.832 cm−1 for samples TG1 and TG4, respectively. Moreover, the lowest half-value layer attained via TG1 and raises from 0.0030 to 3.6684 cm while the highest HVL attained by TG4 and raises from 0.0029 to 3.9696 cm. © 2020 Elsevier B.V.All Authors present their grateful acknowledge to the Universiti Putra Malaysia (UPM), for supporting this work by chemicals and services, which granted by UPM under IPB-9554200. Also, the authors present their grateful acknowledge to the university of Tabuk, Tabuk, Saudi Arabia for supporting this work by some chemicals