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Abstract: LiSr4(BO3)3:0.01Ce3+ phosphor was investigated to assess its potential as a material for measurements of radiotherapeutic doses with electron spin resonance (ESR). The ESR spectrum of the phosphor irradiated with 60Co features five ESR signals. An isochronal annealing experiment has shown that the strongest of these signals is associated with the same trap center as the 473K peak on the TL glow curve of this material. The dose–response is linear in the studied range from 0.89 to 90.30Gy. Fading of the signal was also investigated. [Copyright &y& Elsevier]

Abstract: Polycrystalline powder sample of KSr4(BO3)3 was synthesized by high-temperature solid-state reaction. The influence of different rare earth dopants, i.e. Tb3+, Tm3+ and Ce3+, on thermoluminescence (TL) of KSr4(BO3)3 phosphor was discussed. The TL, photoluminescence (PL) and some dosimetric properties of Ce3+-activated KSr4(BO3)3 phosphor were studied. The effect of the concentration of Ce3+ on TL intensity was investigated and the result showed that the optimum Ce3+ concentration was 0.2mol%. The TL kinetic parameters of KSr4(BO3)3:0.002 Ce3+ phosphor were calculated by computer glow curve deconvolution (CGCD) method. Characteristic emission peaking at about 407 and 383nm due to the 4f05d1 → 2F(5/2, 7/2) transitions of Ce3+ ion were observed both in PL and three-dimensional (3D) TL spectra. The dose–response of KSr4(BO3)3:0.002 Ce3+ to γ-ray was linear in the range from 1 to 1000mGy. In addition, the decay of the TL intensity of KSr4(BO3)3:0.002 Ce3+ was also investigated. [Copyright &y& Elsevier]

Abstract: LiCaBO3 was synthesized by high-temperature solid-state reaction. The influence of different rare earth dopants, i.e. Dy3+, Tb3+, Tm3+ and Ce3+, on thermoluminescence (TL) of LiCaBO3 phosphor was discussed. We studied the TL properties and some dosimetric characteristics of Ce3+-activated LiCaBO3 phosphor in detail. The effect of the concentration of Ce3+ on TL was investigated, the result of which showed that the optimum Ce3+ concentration was 1mol%. The TL kinetic parameters of LiCaBO3:0.01Ce3+ were studied by computer glow curve deconvolution (CGCD) method. The three-dimensional (3D) TL emission spectra were also studied, peaking at 431 and 474nm due to the characteristic transition of Ce3+. We also studied the linearity, annealing condition, reproducibility, fading and different heating rate of the LiCaBO3:0.01Ce3+ phosphor. [Copyright &y& Elsevier]

Abstract: The Sr2Mg(BO3)2 phosphors doped respectively with Tm3+, Tb3+ and Dy3+ as activator were prepared by high temperature solid-state reaction. All the thermoluminescence curves of the phosphors consisted of two isolated peaks and the Dy3+ activated sample exhibited the strongest thermoluminescence intensity. The kinetic parameters of the thermoluminescence of Sr2Mg(BO3)2 :0.04 Dy were calculated employing the peak shape method and 3 dimensional thermoluminescent emission spectra were observed peaking at 480, 579, 662 and 755 nm due to the characteristic transition of Dy3+. In addition, the pre-irradiation heat-treatment and the thermoluminescence dose response of Sr2Mg(BO3)2 :0.04 Dy were investigated. [Copyright &y& Elsevier]

Abstract: Borates LiSr4(BO3)3 were synthesized by high-temperature solid-state reaction. The thermoluminescence (TL) and some of the dosimetric characteristics of Ce3+-activated LiSr4(BO3)3 were reported. The TL glow curve is composed of only one peak located at about 209 °C between room temperature and 500 °C. The optimum Ce3+ concentration is 1 mol% to obtain the highest TL intensity. The TL kinetic parameters of LiSr4(BO3)3:0.01Ce3+ were studied by the peak shape method. The TL dose response is linear in the protection dose ranging from 1 mGy to 1 Gy. The three-dimensional thermoluminescence emission spectra were also studied, peaking at 441 and 474 nm due to the characteristic transition of Ce3+. [Copyright &y& Elsevier]

Abstract: A series of KGd1−x Eu x F4 (x=1, 5, 10, 15, 20, 40, 60, 80 and 100mol%) nanophosphors were prepared by a simple and reproducible hydrothermal route. The structural and morphological properties of the samples were studied by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM), showing uniform nano-sized particles with cubic phase. The excitation spectra disclosed the intrinsic absorption bands of Eu3+ 5L6 state at 393nm and of Gd3+ 6I J state at 272.4nm. From the downconversion (DC) emission spectra, it was found that the optimal Eu3+ concentration was 20mol% and 15mol% under 393nm and 272.4nm excitation, respectively. The nonradiative energy transfer (ET) mechanism is discussed and it turns out that ET of Eu3+–Eu3+ couple and Gd3+–Eu3+ couple occurs mainly via electric dipole–dipole and electric dipole–quadrupole interactions, respectively. From luminescence decay curves, the lifetimes of KGd1−x Eu x F4 nanophosphors are seen to decrease with the increase of Eu3+ concentration. Both the emission spectra and luminescence decay curves show that downconversion ET between Gd3+ and Eu3+ ions is more efficient than that between Eu3+ and Eu3+ ions, thus suggesting potential applications in mercury-free fluorescence lamp and plasma display panel under vacuum ultraviolet (VUV) radiation. [Copyright &y& Elsevier]

Abstract: Polycrystalline powder samples of terbium doped Zn(BO2)2 phosphors were prepared by solid state reaction in the thermal carbon reducing atmosphere at high temperature. The photoluminescence (PL), three-dimensional (3D) TL emission spectrum and dosimetric characteristics following 60Co gamma-rays irradiation were studied. Characteristic emission bands of Tb3+ at about 490, 543, 584 and 620nm, attributed to the 5D4→7F J (J=3, 4, 5, 6) transitions of Tb3+ ions, were observed in the TL and PL emission spectrum. No emission from Tb4+ ions was observed in the TL emission spectrum. The TL-dose response of the powder samples Zn(BO2)2:Tb to 60Co gamma-rays radiation in the dose range from 1 to 100Gy for clinical dose levels was almost linear. The experiment results showed that Zn(BO2)2:Tb has potential use as the materials of gamma-rays thermoluminescence dosimeter (TLD) for clinical dosimetry. [Copyright &y& Elsevier]