محسن محرابی

The pure and Eu2?-doped NaCl crystal were successfully grown by the melt (Czochralski) method. The structural, mechanical and optical properties were characterized by carrying out X-ray diffraction (XRD), micro-hardness, optical absorption, photoluminescence (PL) and thermoluminescence (TL) measurements. The XRD analysis indicates that the Eu2+ ions have been incorporated into the NaCl crystal matrix and the diffraction peak shifts toward lower 2h angle. Hardness measurement has shown a decrease of crystal hardness with indentation load. Optical absorption spectrum has shown the presence of peaks at 211, 224, 231, 255, 320 and 352 nm. Results of PL analysis indicate that the emission peak exists the characteristic peak of bivalent Eu ions corresponding to the t2g(4f65d) -8S7/2(4f7) transition. The TL glow curve of NaCl:Eu2+ crystal has shown two peaks located at 108.6 and 199.6 C with different trap depth, the intensity of the high-temperature peak is found to be larger than the low-temperature one.