Damage Properties Of Yttrium Stabilized Zirconia Crystals Induced By Ion Irradiation

To study the irradiation damage behavior of materials and reveal its internal mechanism is a basic scientific problem in the fields of advanced energy space exploration and so on.The irradiation stability of yttrium stabilized zirconia(YSZ)crystal has important applications in nuclear technology related fields.Study on the evolution characteristics of crystal damage microstructure under different irradiation conditions and clarify its irradiation damage and mechanism.This not only meets the urgent need of clarifying irradiation effects in advanced reactors and other fields,but also broadens the practical application of ion beam technology in micro-nano structure preparation and other fields.The work in this dissertation focuses on evaluating the irradiation-induced damage properties of YSZ crystals irradiated by ions with different energy ranges and masses,Which mainly includes the following:damage properties of YSZ crystals induced by intense electronic energy loss irradiated by heavy ions;damage properties of YSZ crystals induced by nuclear energy loss irradiated by intermediate-mass ions;damage effect of YSZ crystals induced by hydrogen and helium ions and their successive irradiation.The main comems of this dissertation are as follows:YSZ samples were irradiated with 353 MeV Fe13+ and 645 MeV Xe35+,and laws governing the structural and optical properties of high-energy heavy ions irradiated with high charge states arc given.The experiments of XRD.TEM,and AFM combined with the iTS model calculation results show that the threshold of track damage formation is determined by atomic energy deposition under the combined action of electronic energy loss and ion velocity.The atomic energy deposition threshold of isolated spherical damage in YSZ crystal is 1.32 eV/atom.and the atomic energy deposition threshold of the discontinuous track is 1.81 eV/atom.Based on the superposition of kinetic energy and potential energy during irradiation,nano-hillock structure is induced on the surface of zirconia crystal.The results of UV-Vis optical absorption spectra.Raman spectra,and Photoluminescence spectra show that with the increase of ion dose.ion irradiation induces the formation of F+-type and T-type color centers and causes optical band gap reduction.Raman peak intensity reduction,and defect state fluorescence enhancement,etc..which provides technical support for the application of ion irradiation in optical property regulation.YSZ samples were irradiated with 30 MeV Cl5+ and 90 MeV Ar12+,and the damage properties of YSZ crystals induced by tens of MeV intermediate-mass ion irradiation were studied to determine the cause of damage.The prism coupling and XRD method provide preliminary evidence for the existence of nuclear energy loss-induced damage of samples.The combined TEM experimental analysis and iTS model simulations show that the atomic energy deposition in the peak electronic energy loss region is still lower than the melting standard under this irradiation condition,further confirming that the appearance of displacement damage is attributed to nuclear energy loss.The UV-Vis optical absorption test showed that Ar12+irradiation leads to the formation of F+-type and T-type color centers in YSZ samples and the band tail effect induced by Ar12+ irradiation effectively reduces the band gap.This study shows that the displacement damage is consistent with the track damage,and both can induce changes in optical absorption properties.YSZ samples were irradiated with 2.4 MeV He2+ and 1.2 MeV H2+individually and successively to simulate the effect of He2+ and H2+ irradiation on the damaged structure.Prism coupling,XRD,and Raman experiments combined with iWKB simulations show that the refractive index of both the surface and the inside of the sample decrease to different degrees under He2+ and H2+ single and their successive irradiation,and the surface refractive index change is due to the strain along the vertical direction inside the samples caused by irradiation,resulting in positive stretching of the sample surface.Among them,the strong strain induced by H2+ irradiation compared to He2+ irradiation may be due to the lower threshold for the aggregation of H ions to occur in YSZ crystals;compared with single ion irradiation,the refractive index and Raman intensity of the sample irradiated by double ion successive irradiation were decreased significantly,which confirmed that the structural damage induced by He2+ and H2+ successive irradiation was more significant than that of single ion irradiation.