Thermoluminescence properties of strontium-copper co-doping lithiun-borate glass for ionizing radiation application

Thermoluminescent dosimetry (TLD) has become a reliable and promising method used in ionizing radiation-dose measurements nowadays. There are wide range of TLD materials in use and among them the glassy matrix structure represents a potentially attractive system due to the outstanding properties such as good thermal stability, human tissue equivalent properties, relatively low cost, easily shaped and good ability to host luminescent activators in elevated concentrations. Many efforts have been devoted to develop tissue equivalent suitable glassy scintillator materials for ionizing radiation measurements. The aim of the present studies was to determine the influences of dopant (SrCO3) and co-dopant (Cu2O, Mg2O, Na2O, P2O2) on lithium-borate (LB) glasses upon their physical, structure, thermal and TLD properties. Six series of glass compositions xLi2CO3–(100-x)H3BO3, 15Li2CO3–(85–y)H3BO3–ySrCO3,15Li2CO3–(83–z)H3BO3–2SrCO3–zCu2O, 15Li2CO3–(83–u)H3BO3–2SrCO3–uMg2O, 15Li2CO3–(83–v)H3BO3–2SrCO3–vNa2O and 15Li2CO3–(83–w)H3BO3–2SrCO3–wP2O2 with varying concentrations of x, y, z, u, v, w (in mol%) were synthesized using melt quenching technique. The amorphous phase, structure, composition, morphologies, thermal and physical properties of synthesized glass samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), Energy-dispersive X-ray (EDX) spectroscopy, Field emission scanning electron microscope (FESEM) and Differential thermal analysis (DTA) respectively. The TLD properties were measured in terms of thermoluminescence (TL) response, sensitivity, linearity, fading, reusability, minimum detectable dose, and Z-effective. These synthesized glass systems were exposed to various types of ionizing radiations such as Co-60 gamma ray, 6 and 10 MeV electrons, 6 and 10 MV X-ray photons. The XRD patterns confirmed the true amorphous state of all prepared glass samples. The FTIR results show that the structure of the glass samples is that of LB glass. The dopant (SrCO3) and co-dopant (Cu2O) in LB glass were not changing the main feature of the structure. The EDX analyses of samples show that the composition of the glasses is that of LB, its doped and co-doped. The FESEM results show homogeneous morphology. The DTA shows that the prepared glass samples are physically and thermally stable. Samples doped with 2.0 mol% of SrCO3 and 0.01 mol% of Cu2O concentration showed the highest TL efficiency. Furthermore, the co-doped glasses exhibited very significant TL properties such as linear dose response, good reusability, low minimum detectable dose and high sensitivity. The samples also showed good dose linearity characteristic and TL sensitivity in the dose range of 0.5-4.0 Gy when irradiated with 10 MeV electrons. The achieved effective atomic number of glass samples was found to be 9.69 and 11.08 for LB doped with 2.0 mol% of SrCO3 and co-doped with 0.01 mol% of Cu2O, respectively. The relative energy response of both doped and co-doped samples have been calculated theoretically and the results obtained are in good agreement with the experimental ones. In conclusion, the studied glass samples were found to have excellent properties required in TLD applications

Strontium ion concentration effects on structural and spectral properties of Li4Sr(BO3)(3) glass

Optimizing the concentration of host borate glass system to achieve a superior thermal and structural stability is challenging for sundry applications. A series of lithium strontium borate (LSBO) glasses with composition of (85 - x) H3BO3 - 15Li2CO3 - xSrCO3, where x = 5, 7.5, 10, 12.5 and 15 mol% are prepared via melt quenching technique. Synthesized glasses are thoroughly characterized using XRD, FTIR, DTA, FESEM, PL, and UV-vis-NIR measurements to determine the influence of strontium (Sr2+) ion concentration on thermal, physical, and structural properties of the glasses. XRD pattern confirms the amorphous nature of all samples. The FESEM images verify their homogeneous and transmitting surface morphology. Physical properties are determined in terms of glass density, molar volume, molar refractivity, polaron radius, inter-nuclear distance, field-strength, and ion concentration. Glass density is found to increase from 2.53 to 2.95 g/cm3 with increasing Sr2+ ion contents. FTIR spectra exhibit the presence of two fundamental peaks in the range of 700-1070 cm-1 corresponding to the trigonal and tetrahedral stretching vibrations of BO3 and BO4 units. These peaks show a shift with the increase of modifier concentration. DTA results display peaks for glass transition, crystallization and melting at 500, 600 and 900°C, respectively. Prepared samples are highly stable with Hurby parameter ~ 0.5. The direct, indirect band gap and Urbach energy calculated from the absorption edge of UV-vis-NIR spectra lie within 3.4-3.8 eV and 3.84-3.93 eV, 3.84-3.25 eV, respectively. The observed increase in refractive index from 2.17-2.19 is ascribed to the conversion of BO4 into BO3 units. Room temperature PL spectra under 430 nm excitations display two peaks centered at 482 and 526 nm accompanied by slight peak shift towards the lower wavelength due to the formation of new complexes in the glass network. Results are analyzed via different mechanism and compared. Excellent features of the results nominate these compositions potential for solid state lasers, photonic devices, and optical fibers applications

Thermoluminescence response of nanoparticles gold doped lithium borate glass subjected to photon irradiation

The absorption coefficient of Borates glass is much closed to human body tissue. This fact makes borates as an ideal material for thermoluminescence material either for medical or environmental application. In this study, a glass system of 15% Li2CO3+ 85% H3BO3 doped with 0.1mol %nano-gold was prepared by using melt-quenching technique. Undoped and Au doped lithium borate glass samples were exposed to Co-60 gamma ray (1.25 MeV) with various doses ranging from 10 to 60 Gy by using Gammacell 220 excel. Various TL properties such as TL glow curve, linearity and sensitivity of the prepared glass were investigated. From the TL glow curve, it was found that the TL intensity increased by addition of Au into the glass system. The TL intensity of Au doped glass increases about 23 times higher than the undoped glass. The study also shows that the doped borate glass has a linear response subjected to Co-60 gamma irradiation at doses ranging from 10 to 60 Gy. The sensitivity of doped glass is about 22 times higher compared to un-doped glass

Thermoluminescence properties of lithium borate glass subjected to 60CO gamma ray

Glass samples with composition of xLi2CO3-(100-x) H3BO3, with 10 =x = 25 were prepared by melt-quenching technique. The amorphous structure, sample morphology and thermoluminescence (TL) properties of the prepared samples were determined using powder X-ray diffraction (XRD) spectrometer, field emission scanning electron microscope (FE-SEM) and TLD reader, respectively. The samples were irradiated to Co-60 gamma source. The FE-SEM results show that the morphology of the prepared samples was in homogenous and transmitted surface. Furthermore the amorphous phase was confirmed by XRDanalysis. It was also found that the composition of Li2CO3 and H3CO3 affected the TL response and the highest TL response was observed for the sample with composition 15 mol % Li2BO3 and 85 mol % of H3CO3 after being irradiated to 10 Gy gamma ray. The sensitivity of this sample was of about 138.306 nC g-1 Gy-1

Optimization of thermoluminescence response of copper doped zinc lithium borate glass co-doped with Na2O

Establishing the basic procedures that will influence the enhancement of the TL yield of a phosphor is paramount in the issue of dosimetry. Melt quenching method was adopted in synthesizing lithium borate glass modified with ZnO, doped with CuO and codoped with Na2O. The structural and optical properties of zinc lithium borate and some TL properties of copper doped zinc lithium borate were reported in our previous works. The amorphous nature of the prepared glasses was confirmed by x-ray diffraction analysis (XRD). Physical properties of the glass were obtained via Archimedes principle. The copper doped zinc lithium borate was co-doped with different concentration of Na2O (0.025 mol % to 0.1 mol %). The glasses were irradiated with 4 Gy dose of gamma rays using 60Co gamma cell. The highest TL response was recorded against 0.05 mol% concentration of Na2O. The best settings for TLD reading of the proposed TLD were determined. The optimal annealing temperature and time for this composition was found to be 300 oC and 50 min respectively. The best heating rate at which the new TLD can be readout was 3 oC S-1

Thermoluminescence response of nano gold doped lithium borate glass subjected to photon irradiation

This study investigated thermoluminescence (TL) properties of undoped and gold nano-particle doped lithium borate glass subjected to Co-60 gamma irradiation. The TL properties of both glasses were studied and compared in terms of TL glow curves, linearity, sensitivity and reproducibility. A number of samples based on xLi2CO3 + (100 x) H3BO3 , where 10 ≤ x ≤ 25 mol%, have been prepared using melt - quenching technique. The crystalline phases of undoped and doped glasses were identified by X-ray diffraction (XRD) analysis. The results of XRD patterns indicated that the glass samples were amorphous. The best TL-response of undoped lithium borate glass was identified with a composition of 85% H3BO3 + 15% Li2CO3 and this glass composition was doped with 0.1 mol% gold nano-particle. The samples were exposed to Co-60 gamma radiation with doses ranging from 10 Gy to 60 Gy. The glow curves were analyzed to determine various characterizations of TLD’s. The result clearly shows the superiority of gold nano-particle doped lithium borate glass in terms of TL response and sensitivity to produce luminescence compared to undoped lithium borate glass. Gold nano-particle doped glass provides sensitivity of about 22 times compared to the undoped glass. The doped glass has reproducibility about 3.6% after 2 cycles of exposure. The effective atomic numbers, Zeff of undoped and gold nano-particle doped glass were calculated as 7.1 and 59.03, respectively