Limits...
Tracing temperature in a nanometer size region in a picosecond time period.

Nakajima K, Kitayama T, Hayashi H, Matsuda M, Sataka M, Tsujimoto M, Toulemonde M, Bouffard S, Kimura K - Sci Rep (2015)

Bottom Line: This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies.Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position.The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

View Article: PubMed Central - PubMed

Affiliation: Department of Micro Engineering, Kyoto University, Kyoto 615-8540, Japan.

ABSTRACT
Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

No MeSH data available.


Radial density profile of the ion track derived from the observed HAADF-STEM images of a-SiO2 films irradiated with 420 MeV Au ions (solid circles).The intensity profile derived from the observed TEM images is also shown for comparison (dashed line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4543984&req=5

f3: Radial density profile of the ion track derived from the observed HAADF-STEM images of a-SiO2 films irradiated with 420 MeV Au ions (solid circles).The intensity profile derived from the observed TEM images is also shown for comparison (dashed line).

Mentions: Figures 1(b) shows an example of TEM bright field images of the gold-deposited a-SiO2 film observed after irradiation with 420 MeV Au ions. The irradiation was performed on the rear surface, i.e. from the opposite side of the gold deposition (will be referred to as “rear surface irradiation”). Ion tracks are clearly seen as bright spots with a diameter of about 2 nm. The ion tracks were also observed using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The profiles of the observed track images are shown for both TEM and HAADF-STEM in Fig. 3. The TEM profile has an oscillatory structure caused by Fresnel diffraction, indicating the difficulty of deducing quantitative information from TEM images. On the contrary, the HAADF-STEM profile can be directly linked to the density profile. The observed HAADF-STEM profile shows a core-shell structure, namely a low density core (radius 1.6 ± 0.3 nm) surrounded by a high density shell (outer radius 6 ± 1 nm). This is in good agreement with the observation using small angle x-ray scattering17. According to the two thresholds model1718 (see also Supplementary information), the present result suggests that the energy per atom surpasses the melting energy (0.38 eV/atom17) at r < 6 ± 1 nm and boiling energy (1.7 eV/atom17) at r < 1.6 ± 0.3 nm.


Tracing temperature in a nanometer size region in a picosecond time period.

Nakajima K, Kitayama T, Hayashi H, Matsuda M, Sataka M, Tsujimoto M, Toulemonde M, Bouffard S, Kimura K - Sci Rep (2015)

Radial density profile of the ion track derived from the observed HAADF-STEM images of a-SiO2 films irradiated with 420 MeV Au ions (solid circles).The intensity profile derived from the observed TEM images is also shown for comparison (dashed line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543984&req=5

f3: Radial density profile of the ion track derived from the observed HAADF-STEM images of a-SiO2 films irradiated with 420 MeV Au ions (solid circles).The intensity profile derived from the observed TEM images is also shown for comparison (dashed line).
Mentions: Figures 1(b) shows an example of TEM bright field images of the gold-deposited a-SiO2 film observed after irradiation with 420 MeV Au ions. The irradiation was performed on the rear surface, i.e. from the opposite side of the gold deposition (will be referred to as “rear surface irradiation”). Ion tracks are clearly seen as bright spots with a diameter of about 2 nm. The ion tracks were also observed using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The profiles of the observed track images are shown for both TEM and HAADF-STEM in Fig. 3. The TEM profile has an oscillatory structure caused by Fresnel diffraction, indicating the difficulty of deducing quantitative information from TEM images. On the contrary, the HAADF-STEM profile can be directly linked to the density profile. The observed HAADF-STEM profile shows a core-shell structure, namely a low density core (radius 1.6 ± 0.3 nm) surrounded by a high density shell (outer radius 6 ± 1 nm). This is in good agreement with the observation using small angle x-ray scattering17. According to the two thresholds model1718 (see also Supplementary information), the present result suggests that the energy per atom surpasses the melting energy (0.38 eV/atom17) at r < 6 ± 1 nm and boiling energy (1.7 eV/atom17) at r < 1.6 ± 0.3 nm.

Bottom Line: This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies.Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position.The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

View Article: PubMed Central - PubMed

Affiliation: Department of Micro Engineering, Kyoto University, Kyoto 615-8540, Japan.

ABSTRACT
Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

No MeSH data available.