Synthesis and luminescence properties of Tb3+-doped LiMgPO4 phosphor

摘要

Polycrystalline sample LiMg(1-x)PO4:xTb(3+) (x = 0.001, 0.002, 0.005, 0.01, 0.02) phosphor was synthesized via modified solid state method (MSSM). The prepared sample was characterized through XRD pattern (X-ray diffraction) and SEM (scanning electron microscope). Additionally, photoluminescence (PL), optically stimulated luminescence (OSL), thermoluminescence (TL) and other dosimetric properties including dose linearity, reusability and fading were studied. In OSL mode, sensitivity of prepared phosphor was found to be 2.7 times that of LiMgPO4:Tb3+, B (BARC) phosphor and 4.3 times that of alpha-Al2O3:C (BARC) phosphor. The TL glow consists of overlapping peaks in temperature range of 50-400(ay)C and first peak (P-1) was observed at 150(ay)C, second peak (P-2) at 238(ay)C, third peak (P-3) at 291(ay)C and fourth peak (P-4) at 356(ay)C. The TL sensitivity of second peak (P-2) of LiMgPO4:Tb3+ phosphor was compared with alpha-Al2O3:C (BARC) phosphor and found to be 100 times that of the alpha-Al2O3:C (BARC) phosphor. The minimum detectable dose (MDD) was found to be 5.6 mu Gy. Moreover, photoionization cross-sections, linearity, reusability, fading and kinetic parameters were calculated. Also, photoluminescence spectra of LiMgPO4: Tb3+ shows characteristic green-yellow emission exciting at 224 nm UV source.