Fine structure of swift heavy ion track in rutile TiO2

Abstract

Understanding the formation of latent track by energetic heavy ions is important for the fields of nuclear waste disposal, nuclear fuel and modification of materials.However, the details of the mechanism for the track formation in non-amorphizable materials are still being debated. Here, we report on the fine structure formation of latent tracks, which changes from cylinder to sandglass as a function of the ion-penetrating length, in a typical non-amorphizable material, rutile TiO 2 . Based on inelastic thermal spike model, we show that the outflow of molten phase produces the hillocks on surface and the void-rich zone near surface, while at a deep depth, the lack of outflow and the rapid recrystallization result in the absence of tracks. Moreover, the morphology of tracks depends on the velocity of molten phase outflow and recrystallization. Our perspective provides a new interpretation in the radiation damage for both amorphizable and non-amorphizable materials.

Exciton Transitions in Monolayer WS2 Activated by Swift Heavy Ion Irradiation

“…The height of the hillock determined by AFM is considered as an appropriate parameter to describe the behavior of the ion track formation. 73 The average height of the hillocks is about 6 nm for Bi ionirradiated WS 2 /SiO 2 . Considering the thickness of monolayer WS 2 on the SiO 2 substrate, the substrate is assumed to contribute the most to the hillock height.…”

“…62,63 The rapid quenching process of the SHI-caused molten TMDC is accompanied with an epitaxial recrystallization process, which starts along the matrix-molten phase interface and has a similar lattice with initial states. 72,73 Hence, the recrystallization ability of the target material is a critical factor to determine the track morphology, 72,76 which is considered to be related to the intrinsic properties of the materials, such as the lattice structure and atomic diffusion velocity. The complexity of the material structure can be considered as a crude estimate of the recrystallization ability in SHI tracks.…”

“…Figure f illustrates the cross section of the marked hillock indicated in Figure e. The height of the hillock determined by AFM is considered as an appropriate parameter to describe the behavior of the ion track formation . The average height of the hillocks is about 6 nm for Bi ion-irradiated WS 2 /SiO 2 .…”

“…The slowing down process of the ions is through electron–electron and electron–phonon interactions. , The temperature along the cylindrical SHI path is high enough to cause melting to the target material. After the subsequent rapid quenching, latent tracks with permanent damage will be retained in the target material. , The rapid quenching process of the SHI-caused molten TMDC is accompanied with an epitaxial recrystallization process, which starts along the matrix-molten phase interface and has a similar lattice with initial states. , Hence, the recrystallization ability of the target material is a critical factor to determine the track morphology, , which is considered to be related to the intrinsic properties of the materials, such as the lattice structure and atomic diffusion velocity. The complexity of the material structure can be considered as a crude estimate of the recrystallization ability in SHI tracks .…”

2D Slab Models of Nanotubes Based on Tetragonal TiO2 Structures: Validation over a Diameter Range

“…Due to chemical stability, non-toxicity, low cost, and high availability, titanium dioxide is considered the most promising photocatalyst for the degradation of organic pollutants in water and air, as well as for water splitting and hydrogen production [ 30 , 31 , 32 ]. The additional importance of titania is related to its applications as protective coatings in microelectronic and optical devices and as luminescent compounds [ 33 , 34 , 35 , 36 , 37 , 38 ].…”