The research examines the exceptional physical characteristics of Mg3AB3 (A = N, Bi; B = F, Br, I) perovskite compounds through density functional theory to assess their feasibility for photovoltaic applications. Mechanical characterization further supports their stability where out of all the compounds, Mg3BiI3 demonstrates high ductility, while Mg3NF3 and Mg3BiBr3 possess a brittle nature. The calculated elastic constants and anisotropy factors also substantiate their mechanical stability, while there is an observed declining trend in Debye temperature with increase in atomic number. From the electronic point of view, Mg3NF3 can be considered as a wide-bandgap insulator with the bandgap of 6.789 eV, whereas Mg3BiBr3 and Mg3BiI3 can be classified as semiconductors suitable for photovoltaic applications bandgaps of 1.626 eV and 0.867 eV, respectively. The optical characteristics of such materials are excellent and pronounced by high absorption coefficients, low reflectivity, and good dielectrics, which are very important in the collection of solar energy. Among them, Mg3BiBr3 and Mg3BiI3 possess high light absorption coefficient, moderate reflectivity, and good electrical conductivity, indicating that they are quite suitable for applying the photoelectric conversion materials for solar cells. In addition, thermal analysis shows that Mg3NF3 is a good heat sink material, Mg3BiBr3 and Mg3BiI3 are favorable for thermal barrier coating materials. Due to their high absorption coefficients, low reflectance and suitable conductivity, both Mg3BiBr3 and Mg3BiI3 could be regarded as the most appropriate materials for the creation of the next generation of photovoltaic converters.
One of the most well-liked energizing drinks is now tea, which is primarily used in Malaysia. The natural radioactivity in the associated soils where tea plants are cultivated plays a major role in determining the presence of radionuclides in tea leaves. The present study assesses the transfer of radionuclides from soil-to-tea leaves and then estimates the committed effective doses through tea consumption. Tea leaves and the associated soils were obtained from the largest tea plantation area, which is located in the Cameron Highlands, Malaysia. The marketed tea leaves in powdered form were obtained from the supermarkets in Kuala Lumpur. HPGe gamma-ray spectrometry was used to determine the prevailing concentrations of long-lived radioactive materials in tea leaves. Activity concentrations of 226Ra, 232Th, and 40K in tea soils ranged from 49 to 101.7 Bq kg-1, 74.5-124.1 Bq kg-1 and 79.6-423.2 Bq kg-1, respectively, while the respective values in tea leaves are 14.4-23.8 Bq kg-1, 12.9-29.5 Bq kg-1 and 297-387.5 Bq kg-1. Transfer factors of radionuclides showed typical values (<1.0) except for the 40K. The threshold tea consumption rates suggest that one should not consume more than 67 g of tea leaves per day (around 4 g of tea leaves are needed for making 1 cup of tea, so 17 cups per day) to avoid negative health effects. Committed effective doses due to tea consumption are found to be lower (5.18-6.08 μSv y-1) than the United Nations Scientific Committee on the Effects of Atomic Radiation (2000) reference dose guidance limit of 290 μSv y-1 for foodstuffs; however, it should be noted that the guidance limit is recommended for all foodstuffs collectively. Providing data on natural radioactivity in tea leaves grown in Malaysia, this study may help people manage a healthy lifestyle.