The Preparation Of La、 Ce Doped Of Ba₅Ta₄O₁₅ And Its Gamma-ray Shielding Properties Of NR Composities

In 21st century, the nuclear security is the key of the application of nuclear energy, one of the most important is the radiation protection. Many scientists focus on gamma rays protection because of the very short wave lengths and strong penetrating power of gamma rays. Therefore, it is significant to protect gamma rays. Several heavy metal elements are widely used in radiation protection materials, such as lead, bismuth, tungsten and rare earth. In recent year, tantalum is widely concerned because of green environment in radiation protection areas.A single element has weak absorption phenomenon, so our work focus on Lanthanum or cerium doped Ba₅Ta₄O₁₅ and the preparation of the rubber composite material for testing the gamma ray protection performance.In this paper, we synthesized Lanthanum or cerium doped Ba₅Ta₄O₁₅ through the hydrothermal method, and prepared rubber composites contain inorganic powder. It was characterized by XRD, SEM, TEM, XPS, fluorescence （PL）, and other methods to analyze the crystal structure and the optical properties of the lanthanum or cerium ions doped Ba₅Ta₄O₁₅. It was measured by the electronic universal testing machine and NaI （TI） detectors to the inorganic/rubber composite material for mechanics performance and gamma ray protective performance. The results show that the lanthanum or cerium doped Ba₅Ta₄O₁₅ has a smaller spacing and crystal cell parameters. The SEM images show that Ba₅Ta₄O₁₅ exhibits an aggregated hierarchical microstructure composed of a large number of thin nanosheets. The HRTEM images show that the interplannar distance is reduced for pure and lanthanum or cerium doped Ba₅Ta₄O₁₅. The XPS peaks show that the co-existence of Ce3+ and Ce4+ in cerium doped Ba₅Ta₄O₁₅ It is clear that the binding energy of Ba3d slightly shifted to the higher value direction after lanthanum or cerium doing. The photoluminescence shows the the intensity of lanthanum doped Ba₅Ta₄O₁₅ increases while cerium doped decreases. It is contributed to the cancellation of cerium doping. With the irraditon of 241Am, the shielding rate of rubber coposites reaches 38.66%（16mol% cerium coped） and 37.25%（12mol% lanthanum doped） when the proportion of inorganic is about 40%. The mechanical property of rubber is best when the proportion of inorganic is about 30%.