In this paper we describe the thermoluminescence (TL) characteristics of 0.8 mol% Tm3+ doped ZnB2O4phosphors prepared by a wet-chemical method. The TL glow curves of the phosphor sample consisted of ...three peaks located at 181 °C, 213 °C and 351 °C. The glow peak TL temperature (Tm) at which the TL glow peak occurs shifts toward the higher temperature side whilst the heating ramp rate increases and also the peak TL intensity (Im) decreases. The TL glow curves are characterized by evaluating various dosimetric characteristics of scrutinized samples. The Tm−Tstopinvestigations on regenerated TL signals revealed that there are five different traps in the phosphor with energy values in the range of 0.61–1.71 eV. The dose responses increased in a linear way for 3 peaks with the beta-ray exposure in the dose range of 0.11–60 Gy. The process of applying 10 Gy dose was repeated for ten successive irradiation cycles to check reproducibility and the maximum variation was found to be less than 1% from the average value. These results provide valuable knowledge for use of the characteristics of Tm doped ZnB2O4 in dosimetry research.
•ZnB2O4:Tm3+ phosphors were successfully prepared by a wet chemical method.•The TL glow curves of the samples were analysed.•The trap parameters were calculated by IR method combined with Tm−Tstop
In the MgO-Al2O3 system, magnesium aluminate spinel (MgAl2O4) is a technologically significant compound due to its unique properties, including a high melting point, low thermal conductivity, ...excellent thermal shock resistance, chemical inertness, and robust mechanical strength. This compound has diverse applications in refractory materials, catalyst supports, moisture sensors, nuclear techniques, insulating materials, and even military applications. While rare-earth elements are commonly used as dopants in luminescent materials, limited research exists on doping of Tb3+ ions in magnesium aluminate. This study investigates the luminescence properties of Tb3+ doped synthesis magnesium aluminate materials, shedding light on this underexplored area. The combustion method is employed for synthesis, known for producing nano-sized powders with exceptional luminescent properties. Additionally, this study explores Sm3+ ion doping in magnesium aluminate materials and their luminescence properties. Using the combustion synthesis method, structural attributes of Tb3+-doped MgAl2O4 nanophosphors are meticulously examined. Through X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) analyses, coupled with excitation and emission spectra, a comprehensive investigation of the luminescent provide behavior at room temperature is provided. The XRD data reveal Tb3+ doped MgAl2O4 phosphors exhibit a single phase with face centred cubic structure belonging to the Fd3m‾ space group, consistent with the standard JCPDS files (No. 21-1152). Excitation and emission spectra offer valuable insights into the energy transitions within the Tb3+-doped MgAl2O4 phosphors. Furthermore, the study explores the effects of varying Tb3+ ion concentrations on the luminescent properties, revealing an optimal doping concentration of 5 wt% Tb for maximizing emission intensity. Concentration quenching, primarily attributed to dipole-dipole (d-q) interactions, is observed at higher Sm3+ concentrations. In conclusion, this research enhances our understanding of rare-earth ion doping in luminescent materials and highlights the potential applications of Tb3+-doped MgAl2O4 nanophosphors, which offer promise for various technological applications, including lighting and displays.
In this paper we describe the thermoluminescence (TL) characteristics of 0.8 mol% Tm
doped ZnB
O
phosphors prepared by a wet-chemical method. The TL glow curves of the phosphor sample consisted of ...three peaks located at 181 °C, 213 °C and 351 °C. The glow peak TL temperature (T
) at which the TL glow peak occurs shifts toward the higher temperature side whilst the heating ramp rate increases and also the peak TL intensity (I
) decreases. The TL glow curves are characterized by evaluating various dosimetric characteristics of scrutinized samples. The T
-T
investigations on regenerated TL signals revealed that there are five different traps in the phosphor with energy values in the range of 0.61-1.71 eV. The dose responses increased in a linear way for 3 peaks with the beta-ray exposure in the dose range of 0.11-60 Gy. The process of applying 10 Gy dose was repeated for ten successive irradiation cycles to check reproducibility and the maximum variation was found to be less than 1% from the average value. These results provide valuable knowledge for use of the characteristics of T
doped ZnB
O
in dosimetry research.
With the aid of thermoluminescence (TL), we have extensively studied YAl3(BO3)4 host matrices incorporated with Tb3+ at different doping contents, which have been produced by combustion. The measured ...the TL glow curves exposed to beta rays at different doses consisted of four broad peaks located at around 76, 126, 230, and 378 °C. The peak maximum of the 230 °C TL peak shifts toward higher temperatures after 5 Gy beta irradiation while the other peak maxima almost remain constant. It is peculiar that 230 °C peak maximum shifts to higher temperatures with increased radiation dose and can be attributed to the multiple phases of the sample. A TL glow curve exhibits a proportional increase in intensity with increased the heating rate. A discussion of the possible causes of this pattern is provided. Observed peaks using the Tm─Tstop method are due to the presence of a quasi-continuous distribution of traps. The parameters of the traps have also been estimated using various heating rate methods in excellent agreement with one another.
•The effect of heating rate on the glow curve of YAl3(BO3)4:Tb was studied.•The activation energy and the frequency factor were analysed using VHR method.•Peaks from Tm-Tstop are due to the presence of quasi-continuous distribution of traps.
La2MoO6 orange-red phosphors with high efficiency incorporated with Eu, Dy and Sm have been synthesized through a gel combustion method. The influences of rare earth doping in synthesized samples ...were analysed by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and cathodoluminescence. Rare earth doped La2MoO6 samples show strong emission bands in the range of 400–750 nm and optimal doping concentration for all samples was 2 mol%. La2MoO6 host doped Eu ion showed intense and predominant emission peaks in 450–750 nm range. The electrical multipolar interaction contributed to the non-radiative energy transfer between Eu3+ ions in La2MoO6 host matrix. Sm doped La2MoO6 host exhibited orange-red CL emission peaks at 564, 608, 652 and 708 nm La2MoO6:Dy3+ phosphor displayed emissions at 484, 574 and 670 nm, respectively. The observed intense and sharp emission peaks indicate that La2MoO6 is promising host for lanthanides doped phosphor materials in the applications of optoelectronic.
•Eu3+, Sm3+ and Dy3+ activated La2MoO6 phosphors are synthesized by gel combustion method.•Optimal doping concentration for all samples was 2 mol%.•Cathodoluminescence properties of Eu3+, Sm3+ and Dy3+ activated La2MoO6 phosphors are discussed.
•ZnB2O4:Sm3+ phosphors were synthesized by low temperature chemical synthesis method.•The Thermoluminescence properties were studied by beta excitation source.•Trapping parameters were determined ...using different methods.
This study is mainly centered on thermoluminescence (TL) behavior under beta excitation at room temperature (RT) of Sm3+ activated ZnB2O4 phosphors synthesized by low temperature chemical synthesis method. The prepared phosphors were characterized by the X-ray powder diffraction (XRD) method. The effects of dopant concentration, beta radiation dose (0.115–69 Gy) and heating rate (0.5–10 °C/s) on TL intensity of Sm3+ doped ZnB2O4 phosphors and reproducibility are investigated using a lexsyg smart TL/OSL reader system. The activation energy values, E obtained from the analysis of the TL glow curve were calculated with initial rise (IR) method and peak shape (PS) method over the deconvoluted glow curves. The Ea–Tstop and CGCD methods indicated that the glow curve of this phosphor is the superposition of at least six components, which were called to as P1–P6, in the temperature range between RT and 400 °C. The results reveal that 2% Sm3+ doped ZnB2O4 gives optimum TL response, the relative intensity of the glow peak increases linearly with increase of beta dose and, the peaks of TL glow curves shift towards the higher temperature side with increase in heating rate as the total area under the glow peak remains the same. The maximum variation of reproducibility for ten successive irradiation cycles of 20.7 Gy is less than 3% from the average value and the sample doped 2% Sm3+ shows a good stability for the reusability. Additionally, the results obtained from IR and PS methods indicates that the complex glow curve is composed of six distinguishable peaks.
Here we report a detailed structural analysis, and properties of the cathodoluminescence (CL), photoluminescence (PL) and 3D thermoluminescence spectra of the Tm3+ incorporated ZnB2O4 phosphor ...successfully synthesized through wet-chemical synthesis. The formation of a single-phase compound is verified through X-ray diffraction (XRD) studies. The phosphor shows an efficient blue emission located at 458 nm corresponding to 1D2→3F4 under both a low voltage electron beam and UV excitation. The optimal concentration of the doped Tm3+ is 0.5 mol% in CL and PL measurements. The corresponding concentration quenching mechanism is confirmed to be a multipole-multipole interaction, and the critical distance between Tm3+ ions is estimated to be 34 Å. Incorporating Li+ remarkably enhances the luminescence intensity probably because of the charge compensation effect. Li ions are speculated to fill the defects in the ZnB2O4 host and then the excitation energy transfers from the host to Tm3+. Surprisingly, the thermoluminescence spectra of ZnB2O4:Tm3+ and Li+ co-doped ZnB2O4:Tm3+ recorded in the temperature range 30–400 °C follow a different pattern compared with PL and CL data. The dominant signals come from Tm3+ sites. Above room temperature, the Tm3+ ions do not show the peak temperature movement, but do exhibit a different pattern with the addition of co-doped Li+ ions. These results indicate that these phosphors are promising candidates for luminescence-based optoelectronic devices.
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•Li co-doped ZnB2O4:Tm3+ phosphors were synthesized by wet chemical method.•Structural and luminescence properties were conducted by XRD, PL, CL and 3DTL.•Luminescence enhancement was realized by charge compensation.•The effects of temperature on Tm and Li co-doped luminescence properties were also discussed.
•Anomalies in heating rate effects were observed in rock salt.•Rock salt exhibited a complex spectral TL glow curve.•Glow curve deconvolution of natural rock salt comprised of five peaks.•Detailed ...studies of kinetic parameters of rock salt from Tuzluca-Turkey.
In this work, thermoluminescence (TL) characteristics and kinetic parameters of naturally occurring rock salts were presented. The samples were crushed and compressed into pellets before being irradiated with beta radiation doses ranging between 0.1 Gy and 15 Gy. TL responses exhibited four peaks at about 95 °C, 182 °C, 265 °C, and 360 °C in the glow curve. By increasing the heating rates, we observed an increase in the peak maximum temperature and the area of each peak as well as in the full width half maximum (FWHM), which shows an anomalous heating-rate effect. Taking a rock salt sample, the standard deviation was less than 1%, which was a good indication of repeatability. Using the initial rise (IR) and variable heating rate (VHR) approaches, the trapping parameters were calculated. The findings suggest that salt samples from the Tuzluca district in Turkey may be useful as radiation dosimeters.
Hydroxyapatite (HAP) was selected as the host material and synthesized using a sonication chemical method. The effect of Dy3+ ion doping concentrations (0.25, 0.5, 1, 2, 3, 4, 5, 7, and 10 wt%) on ...the structure and thermoluminescence was examined. The TL properties of Dy3+ doped HAP were also studied, including dose response, repeatability, and heating rate. Based on the glow curves of samples with a heating rate of 2 °C/s after beta irradiation to 20 Gy, three effective peak maxima appeared to make up the glow curves located at around 84, 190, and 318 °C. However, four levels of activation energy were observed by Tm-Tstop analysis. The kinetic analysis of four peaks obtained via computerized glow curve deconvolution revealed trap depths of 0.80, 0.95, 1.20, and 1.51 eV, with corresponding frequency factors of 1010, 1011, 1012, and 1011 s−1, respectively. Parallel investigations using the initial rise and variable heating rate approaches yielded comparable trap depth estimates. The dose dependence of the glow curves was determined to be linear across the 0.1–20 Gy range.
•Dy doped HAP phosphor samples were analysed by sonication chemical method.•The kinetic analysis of glow peaks in HAP:Dy3+ is reported.•Analysis of glow peaks was done by glow-curve deconvolution, VHR and Tm-Tstop.•Corresponding activation energies found were 0.80, 0.95, 1.20 and 1.51 eV.
This study examines the thermoluminescence (TL) properties exhibited by hydroxyapatite (HAp) samples. The HAp samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy ...(SEM) analyses. XRD results confirm that Hap corresponds to a hexagonal structure with a space group of P63/m. The study emphasizes the critical role of appropriate band-pass filters in TL measurements and explores the dose-dependent behavior of TL glow peaks. Examining the impact of varying heating rates (HR) on TL peak intensities revealed a positive correlation between HR and TL maximum peak temperatures, accompanied by a decrease in TL intensities. Notably, no thermal quenching effect was observed in HAp samples. The activation energy values were 0.51, 1.12, and 1.57 eV for Hoogenstraaten's method and 0.55, 1.19, and 1.65 eV for the Booth-Bohun-Porfianovitch method, demonstrating their consistency and robustness. Additionally, Tm-Tstop analysis was employed to identify distinct trap levels and calculate their respective activation energies. This study establishes a solid foundation for characterizing TL properties in HAp samples, shedding light on their potential applications in various fields. The findings provide valuable insights for the design and development of efficient catalysts for diverse applications.
•Finding TL activation energy using Hoogenstraaten's VHR and Booth-Bohun-Porfianovitch methods.•Temperature lag boosts accuracy in activation energy calculation.•Determining activation energy through the IR method.•No thermal quenching.•Exploring HAp TL properties reveals dose-dependent behavior and thermal stability.
