Thermoluminescence study of CaNa2 (SO4 )2 phosphor doped with Eu3+ and synthesized by combustion method

Investigations of thermoluminescence characteristics of SrAlBO4 :Eu3+ phosphors irradiated with gamma rays and carbon ion beam

A series of SrAlBO4 :Eu phosphors doped with different concentrations of Eu (0.1, 0.3, 0.5, 0.7, 1.0 mol%) was synthesized using a solid-state diffusion method, and their thermoluminescence (TL) properties were analyzed for gamma and carbon ion irradiation. The phase purity, morphological properties, vibrational features, and thermal stability of the prepared sample were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric/differential thermal analyzer (TG/DTA) techniques, respectively. The TL properties of the proposed materials showed broad dosimetric bands, peaking at 202°C for 0.12 kGy gamma irradiation. The highest TL intensity was obtained for a 0.7 mol% concentration of Eu ions under gamma irradiation. Furthermore, the glow curve of the proposed materials showed a broad emission band, centred at 148°C under carbon ion beam irradiation and exhibited the highest emission intensity for a 0.1 mol% Eu concentration. In addition, the dosimetric trapping parameters of the prepared samples such as symmetry factor, order of kinetics, activation energy, and frequency factor, were analyzed using various methods such as Chen's peak shape method, initial growth method, and the Ilich method. The obtained results of the samples showed the potential for dosimetric application.

Novel red color emitting Ca0.995 Mg2 (SO4 )3 :0.5Eu2+ phosphor under UV, blue and green excitation for plant growth LEDs

In the recent few years, Eu²⁺ and Mn⁴⁺ activated phosphors are widely used as potential color converters for indoor plant cultivation lighting application due to their marvellous luminescence characteristics as well as low cost. In this investigation, we are synthesized novel red color emitting Ca_(2-x) Mg₂ (SO₄ )₃ : xmol% Eu²⁺ (x = 0-1.0 mol%) phosphors via solid-state reaction method in reducing atmosphere. The PL excitation spectra of synthesized phosphors exhibited a broad excitation band with three excitation bands peaking at 349 nm, 494 nm and 554 nm. Under these excitations, emission spectra exhibits broad band in the red color region around 634 nm. The PL emission intensity were measured for different concentration of Eu²⁺ . The maximum Eu²⁺ doping concentration in Ca₂ Mg₂ (SO₄ )₃ host was observed for 0.5 mol%. According to Dexter theory, it was determined that dipole-dipole interaction is responsible for concentration quenching. The luminous red color emission of the sample was confirmed by CIE color coordinate. The results of PL excitation and emission spectrum of prepared phosphors are well-matched with excitation and emission wavelengths of phytochrome P_R . Therefore, as per the entire investigation and obtained results it was concluded that the synthesized Ca_0.995 Mg₂ (SO₄ )₃ :0.5mol%Eu²⁺ phosphor has huge potential for plant cultivation application.