TL and PL in BaSr(SO₄)₂:Eu mixed sulphate

Abstract

A highly sensitive thermoluminescent (TL) phosphor based on BaSr(SO 4 ) 2 : Eu has been developed. The phosphor was recrystallized from H 2 SO 4 solution by evaporation. Photoluminescence studies of this mixed-sulphate phosphor show that Eu is incorporated in the host in its divalent (emission at 383 nm) as well as trivalent (emissions at 575 and 731 nm) form due to 4f 6 5d → 8 S 7/2 and 5 D 0 → 7 F j transitions, respectively. The intensity of the 383 nm band increases with increasing irradiation, while that of the 731 nm band decreases, showing Eu 3+ → Eu 2+ conversion. The TL glow curve of the BaSr(SO 4 ) 2 : Eu material shows a single peak at 470 K along with a small shoulder at around 428 K. The relative intensities of these peaks are found to vary with γ-ray exposure. The TL sensitivity of the mixed-sulphate phosphor is nearly 2.5, 7 and 1.2 times higher than those of BaSO 4 : Eu, SrSO 4 : Eu and CaSO 4 : Dy phosphors, respectively. The annealing temperature and the impurity concentration effects are also studied.Rare earth-doped alkaline earth sulphates are known to be good thermoluminescence (TL) materials for use in the dosimetry of ionizing radiations. They have been studied for quite some time in order to improve their luminescent properties and to understand the phenomenon in more detail [1][2][3][4][5][6]. Dixon and Ekstrand [2, 3] have studied the luminescence of Dy 3+ and Tm 3+ rare earth-activated BaSO 4 and SrSO 4 . Poort and Blasse [7] have studied the influence of the host lattice on the luminescence of divalent Eu. Lizzo et al. [4] have studied the luminescence of Yb 2+ in alkaline earth sulphates (MSO 4 , where M = Ca, Sr and Ba). Others have studied some mixed-sulphate systems with a view to their applications in the dosimetry of high-energy radiations using the TL technique [8][9][10][11][12][13]. However, the phenomenon of TL is so complex that further work is required for its better understanding.Rare earth (RE) ions can exist in different valence states. The changes in such states induced by highenergy irradiation have also been much studied. A large number of papers can be found in the literature on this subject. In several TL dosimetry (TLD) phosphors, radiation-induced conversion of RE 3+ → RE 2+ has been claimed to play an important role as these ions show different photoluminescence (PL) characteristics [14]. They have been studied not only from the application point of view (they have been proposed for radiophotoluminescence (RPL) [15] and UV dosimetry [16]), but also for understanding the phenomenon itself in more detail. This has been studied for a long time, and models have been proposed

Excitation of thermoluminescence in Eu doped Ba0.12Sr0.88SO4 nanophosphor by low energy argon ions

“…al. [9] for g-ray irradiation. They found a prominent TL glow peak at 470 K along with small shoulder at around 428 K. Hence, there is no one-to-one correspondence in the position of the peaks in both the cases.…”

“…It has been reported that mixed sulphate phosphors have well-desired characteristics like a high-temperature glow peak, linear response with ionizing radiation exposure, low fading and an easy method of preparation. Salah et al [9] explained that TL sensitivity of BaSr(SO 4 ) 2 :Eu is several times higher than that of the Ba and Sr sulphates. They also found that the optimum concentration of Eu is at 0.1 mol %.…”

Nano-barium–strontium sulfate as a new thermoluminescence dosimeter

“…It has been reported that mixed sulfate phosphors have well-desired characteristics like a high-temperature glow peak, linear dose response with ionizing radiation, low fading and an easy method of preparation [7][8][9]. Salah et al [10] have shown that TL sensitivity of BaSr(SO 4 ) 2 :Eu is several times higher than that of the Ba and Sr sulfates. They also found that the optimum concentration of Eu is 0.1 mol%.…”

Thermoluminescence Charcteristics Studies of Phosphor Material With Antibacterial Activity

“…It has been found that composite sulfates establish a type of TL phosphorus with better execution. For example, K2Ca2 (SO4)2: Eu [26], K3Na (SO4)2: Eu [27], Ba0 .97Ca0.03SO4: Eu [28], BaSrSO4: Eu [29] and K2Ca2(SO4)2: Eu, K2Ca2(SO4)2: Eu, Dy [30] is considered an exceptionally subtle TLD phosphorus. Dysprosium sesquioxide, Dy2O3 is a basic highly insoluble and thermally stable material [31].…”