• 제목/요약/키워드: DASF

검색결과 2건 처리시간 0.015초

Characterization of glasses composed of PbO, ZnO, MgO, and B2O3 in terms of their structural, optical, and gamma ray shielding properties

  • Aljawhara H. Almuqrin;M.I. Sayyed;Ashok Kumar;U. Rilwan
    • Nuclear Engineering and Technology
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    • 제56권7호
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    • pp.2842-2849
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    • 2024
  • The amorphous glasses containing PbO, ZnO, MgO, and B2O3 have been fabricated using the melt quenching technique. The structural properties have been analysed using the Fourier-transform infrared (FTIR) and Raman spectroscopy. Derivative of Absorption Spectra Fitting (DASF) method have been used to estimate the band gap energy from the UV-Vis absorption data which decreases from 3.02 eV to 2.66 eV with increasing the concentration of the PbO.The four glass samples 0.284 and 0.826 MeV showed unique variations in terms of gamma attenuation ability. LZMB4 glass sample proved to be the mist effective in terms of shielding of gamma radiation as it requires little distance compared to LZMB3, LZMB2 and LZMB1 to attenuate. RPE revealed a raise with increase in the thickness of the material and reduces as the energy raises. TF is superior in LZMB1 compared to LZMB2, LZMB3 and LZMB4, confirming that, LZMB4 will attenuate better. The ZEff of the materials was seen falling as the energy increases, confirming that the linear attenuation coefficient of the glass materials decreases when the energy is increased. The results confirmed that, glass material LZMB4 is the best option especially for gamma radiation shielding applications compared to LZMB3, followed by LZMB2, then LZMB1.

Temperature Driven Phase Transition of Organic-Inorganic Halide Perovskite Single Crystals

  • Byun, Hye Ryung;Kim, Hyo In;Byun, Su Jeong;Park, Dae Young;Jeong, Mun Seok;Byeon, Clare Chisu
    • Journal of the Korean Physical Society
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    • 제73권11호
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    • pp.1729-1734
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    • 2018
  • Organic-inorganic halide perovskite single crystals undergo phase transition of being cubic, tetragonal, or orthorhombic depending on the temperature. We investigated the $CH_3NH_3PbBr_{3-x}I_x$ single crystals grown by the inverse temperature crystallization method with temperature-dependent UV-Vis absorption and photoluminescence. From the temperature-dependent absorption measurement, the optical band gap is extracted by derivation of absorption spectrum fitting and Tauc plot. In our results, $CH_3NH_3PbBr_{3-x}I_x$ single crystals show that an abrupt change in optical band gap, PL peak position and intensity appears around 120 K - 170 K regions, indicating the phase transition temperature.