Abstract:
The aim of this study is to determine changes in the near-surface layer of ZrO2 ceramics caused by
irradiation with low-energy He2+ ions, as well as the associated formation of defects and structural
deformations. During the experimental work conducted, it was established that the accumulation of
deformation-structural distortions is of two stage nature, having a direct dependence on irradiation
fluence and, therefore, on atomic displacement value. It was determined that at small atomic
displacement values(less than 10 dpa), the main mechanisms of structural distortions are caused by
tensile residual stresses, the value of which is less than 0.1 GPa. At the same time, the deformation
distortion of chemical bonds has a pronounced anisotropy associated with a more pronounced
distortion of the Zr–OI chemical bonds, the distortion of which results in the formation of vacancy
defects in the form of VO. During determination of alterations in optical characteristics depending on
the atomic displacement value, it was found that the dominant role at small values of dpa (less than 10
dpa)is played by point defects, which influence the formation of obstacles in the form of absorbing
centers. In this case, an increase in the irradiation fluence above 1017 ion cm−2 results in a growth in
the linear refractive index, the change of which has a direct correlation with the value of residual
stresses in the damaged layer. Certain dependencies of changes in structural features and their
relationship with deformation distortions, as well as the accumulation of vacancy defects, can
subsequently be used to predict the potential of using these ceramics as materials for new generation
nuclear reactors.
