Structural damage response of lanthanum and yttrium aluminate crystals to nuclear collisions and electronic excitation:Threshold assessment of irradiation damage

A comparative analysis is performed on the structural damage response and associated mechanisms in lanthanum aluminate and yttrium aluminate crystals under various irradiation conditions by a combination of experimental and theoretical approaches.Under low-energy Au~+irradiation,the damage accumulation curve shows a higher damage rate for LaAlO_(3)crystals than YAlO_(3)crystals.The relatively low irradiation tolerance of LaAlO_(3)to the action of nuclear collisions is ascribed to the large amorphization cross-section and effective cross-section for defect-stimulated amorphization.Under swift Ar^(12+),Ni^(19+)and Kr^(17+)irradiation with different ion energies and velocities,the formed highly-disordered/amorphous latent tracks with different morphologies in pristine and predamaged crystals are discussed,and the corresponding electronic energy loss and lattice temperature thresholds are quantitatively determined.Compared to YAlO_(3),LaAlO_(3)exhibits lower sensitivity and higher damage tolerance to the electronic energy loss process,attributing to its relatively high recrystallization efficiency during the rapid quenching process.Furthermore,the introduction of lattice defects into LaAlO_(3)and YAlO_(3)crystals considerably enhances the sensitivity and intensity of thermal spike response to the electronic energy loss,and the induced effective modification of track morphologies demonstrates the synergistic effect between the electronic energy loss and pre-existing defects created by nuclear collisions.In this case,even under the action of electronic energy loss below the threshold,the lattice temperature in the nuclear-collision damaged crystalline system could still meet the criterion for track production.The irradiation energy deposited to atoms and induced lattice temperature evolution discussed in this work provide a deeper insight into the complex processes involved in irradiation-induced latent track behaviors.

Electronic energy loss and ion velocity correlation effects in track production in swift-ion-irradiated LiNbO_(3):A quantitative assessment between structural damage morphology and energy deposition

The primary motivation for studying how irradiation modifies the structures and properties of solid materials involves the understanding of undesirable phenomena,including irradiation-induced degradation of components in nuclear reactors and space exploration,and beneficial applications,including material performance tailoring through ion beam modification and defect engineering.In this work,the formation mechanism of latent tracks with different damage morphologies in LiNbO_(3)crystals under 0.09-6.17 Me V/u ion irradiation with an electronic energy loss from 2.6-13.2 ke V/nm is analyzed by experimental characterizations and numerical calculations.Irradiation-induced damage is preliminarily evaluated via the prism coupling technique to analyze the correlation between the dark-mode spectra and energy loss profiles of irradiated regions.Under the irradiation conditions of different ion velocities and electronic energy losses,different damage morphologies,from individual spherical defects to discontinuous and continuous tracks,are experimentally characterized.During ion penetration process,the ion velocity determines the spatiotemporal distribution of deposited irradiation energy induced by electronic energy loss,meaning that the two essential factors including electronic energy loss and ion velocity coaffect the track damage.The inelastic thermal spike model is used to numerically calculate the spatiotemporal evolutions of energy deposition and the corresponding atomic temperature under different irradiation conditions,and a quantitative relationship is proposed by comparison with corresponding experimentally observed track damage morphologies.The obtained quantitative relationship between irradiation conditions and track damage provides deep insight and guidance for understanding the damage behavior of crystal materials in extreme radiation environments and selecting irradiation parameters,including ion species and energies,for ion beam technique application in atomic-level defect manipulation,material modification,and micro/nanofabrication.

电子能损引起的潜径迹

潜径迹是电子能损在凝聚态物质中引起的重要效应之一。给出了一个关于引起潜径迹电子能损阈值、损伤截面以及径迹形貌的综合评述。

快重离子电子能损引起的缺陷产生及其后续效应

快重离子与凝聚态物质相互作用是核物理研究的重要领域之一,近年不断有新的现象发现。文章综述了快重离子电子能损效应研究的历史和概况,重点介绍了快重离子辐照引起的缺陷产生和退火、潜径迹的形成、塑性形变、相变等现象以及相关理论模型,对该领域未来发展趋势给出展望。

1.23GeV Fe离子在C_(60)薄膜中形成潜径迹的Raman谱分析

用能量为1.23GeV的快Fe离子辐照了多层堆叠的C60薄膜。用Raman散射技术分析了快Fe离子在C60薄膜中由强电子激发引起的效应,主要包括辐照引起C60分子的聚合及其高温、高压相(HTHP)的形成,和在髙电子能损下C60晶体点阵位置上的C60分子向非晶碳的转变。由此演绎出了快Fe离子在C60薄膜中的损伤截面或潜径迹截面σ和潜径迹的半径Re,及其随沉积在电子系统中的能量密度的变化而变化的规律。