Controllable Synthesis And Gamma Radiations Protection Properties Of PbWO₄ Fiber And Its Ce And Eu Doped Structures

γ-rays is a kind of high-energy photons that can cause cell damage,cancerization and even genetic mutations in organisms.It poses potential threat to human health and environmental safety,and needs to be effectively protected from.At present,flexible materials forγ-rays protection have various disadvantages such as bulkiness,and then its wearable products are difficult to meet the current requirements of radiation protection.The root cause is that the functional particles forγ-rays protection have low absorption coefficients and single function.Therefore,developing the functional particles with highγ-rays absorption coefficients and multi-functionality helps to improve the overall performance of flexible materials forγ-rays protection.Firstly,two heavy elements Pb and W with high absorption coefficient ofγ-rays were combined by precipitation method to obtain PbWO₄ crystals with controlled morphology and size.In the process of regulating the crystal structure of PbWO₄,the silane coupling agent（3-mercaptopropyl）-trimethoxysilane（KH590）is used as a surfactant to drive the PbWO₄crystal to grow in a specific direction.XRD,SEM and TEM tests show that PbWO₄ crystals are firstly transformed from initially irregular PbWO₄ nanoparticles into PbWO₄ nanofibers with uniform morphology and uniformity,and then converted into biconical（normal octahedron）PbWO₄ crystallites.In addition,the performance of PbWO₄ crystals was evaluated using an electronic universal testing machine,a thermal conductivity analyzer,and a gamma detector.The results show that PbWO₄ nanofiber not only has excellentγ-ray protection performance,but also has good thermal conductivity and mechanical properties.It can improve the overall performance of flexible materials forγ-rays protection and help to expand its application in wearable products for radiation protection.Secondly,Pb has a weak absorption region（40keV⁸8keV）forγ-ray attenuation.To meet the requirements of low-energyγ-ray protection,here Ce and Eu rare earth doped PbWO₄crystals are performed by precipitation method.XRD,SEM,TEM,XRF and PL techniques were used to characterize and test the structure,morphology and composition of PbWO₄crystals before and after doping.XRD results show that the main peak position of Ce doped PbWO₄ crystal shifts to the right first and then to the left slightly,while that of Eu doped PbWO₄ crystal shifts slightly to the large angle.SEM and TEM images show that they are doped with Ce and Eu.The amount of PbWO₄ crystals changed significantly,and the lattice fringe spacing decreased.XRF results show that Ce ions can replace part of Pb ions and W ions,and Eu ions can only replace Pb ions.γ-rays shielding results show that theγ-rays protection performance is improved after doping.When the Ce and Eu doping amounts are10 mol%and 15 mol%,respectively,theγ-rays attenuation coefficient is the largest,which is2.61 cm²/g and 2.52 cm²/g.