Publisher’s Note: Anisotropy of Co nanoparticles induced by swift heavy ions [Phys. Rev. B<b>67</b>, 220101 (2003)]

D’Orléans, C.; Stoquert, J.P.; Estournès, Claude; Cerruti, C.; Grob, Jean‐Jacques; Guille, J.; Haas, Fernando; Müller, D.; Richard‐Plouet, Mireille

doi:10.1103/physrevb.68.029903

Cited by 15 publications

(24 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The vaporized material must also come out of the matrix for the observed aggregation to take place. In silica glass SHI irradiation can result in a melting of a cylindrical zone around the beam path which, because of the pressure imbalance [20], can result in a squeezing out of the evaporated Au atoms [18]. In such a case, it is not obvious that the expanding system could be in a thermalized state, with a temperature above a critical value, T C , before going through a liquidgas phase transition as proposed by Urbassek [9].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Observation of a Universal Aggregation Mechanism and a Possible Phase Transition in Au Sputtered by Swift Heavy Ions

et al. 2008

View full text Add to dashboard Cite

Two exponents, δ, for size distribution of n-atom clusters, Y (n) ∼ n −δ , have been found in Au clusters sputtered from embedded Au nanoparticles under swift heavy ion irradiation. For small clusters, below 12.5 nm in size, δ has been found to be 3/2, which can be rationalized as occurring from a steady state aggregation process with size independent aggregation. For larger clusters, a δ value of 7/2 is suggested, which might come from a dynamical transition to another steady state where aggregation and evaporation rates are size dependent. In the present case, the observed decay exponents do not support any possibility of a thermodynamic liquid-gas type phase transition taking place, resulting in cluster formation.

show abstract

mentioning

confidence: 99%

“…There is also no dissipation of heat into the insulating surrounding matrix. Simulations indicate this to be true leading to vaporization of smaller particles [20], some of which get attached to other NPs leading to Ostwald ripening.…”

mentioning

confidence: 99%

Observation of a Universal Aggregation Mechanism and a Possible Phase Transition in Au Sputtered by Swift Heavy Ions

et al. 2008

View full text Add to dashboard Cite

show abstract

“…This phenomenon has been reported for several metals under a wide range of SHII conditions, with Refs. [7][8][9][10][11][12][13][14][15][16][17] citing selected examples. Freestanding metallic NPs irradiated under comparable conditions do not change shape, demonstrating the embedding a-SiO 2 matrix must have a role in the shape transformation process [8,17].…”

mentioning

confidence: 99%

Role of Thermodynamics in the Shape Transformation of Embedded Metal Nanoparticles Induced by Swift Heavy-Ion Irradiation

et al. 2011

View full text Add to dashboard Cite

Swift heavy-ion irradiation of elemental metal nanoparticles (NPs) embedded in amorphous SiO 2 induces a spherical to rodlike shape transformation with the direction of NP elongation aligned to that of the incident ion. Large, once-spherical NPs become progressively more rodlike while small NPs below a critical diameter do not elongate but dissolve in the matrix. We examine this shape transformation for ten metals under a common irradiation condition to achieve mechanistic insight into the transformation process. Subtle differences are apparent including the saturation of the elongated NP width at a minimum sustainable, metal-specific value. Elongated NPs of lesser width are unstable and subject to vaporization. Furthermore, we demonstrate the elongation process is governed by the formation of a molten ion-track in amorphous SiO 2 such that upon saturation the elongated NP width never exceeds the molten ion-track diameter. Ion-solid interactions during swift heavy-ion irradiation (SHII) are dominated by inelastic processes in the form of electron excitation and ionization while, in contrast, the influence of elastic processes such as ballistic displacements is negligible. Macroscopically, amorphous SiO 2 (a-SiO 2 ) undergoes a volume-conserving anisotropic deformation when subjected to SHII such that thin freestanding layers contract and expand, respectively, in directions parallel and perpendicular to that of the incident ion [1]. The viscoelastic model [2,3], based on a transient thermal effect, successfully explains this so-called ion hammering. Microscopically, energy is deposited along the ion path, from incident ion to matrix electrons, and is then dissipated within a narrow cylinder of material surrounding the ion path. The heat flow in both the electron and lattice subsystems is well described as functions of time and radial distance by the inelastic thermal spike (i-TS) model [4,5]. When the temperature of the lattice exceeds that required for melting, the material along the ion path is molten and upon quenching an ion track is formed. Recently, we measured the molten ion-track diameter in a-SiO 2 as a function of electronic stopping power [6]. The ion-track radial density distribution consisted of an under-dense core and over-dense shell (relative to unirradiated material), the formation of which was attributed to a quenched-in pressure wave emanating from the ion-track center [6].Elemental metal nanoparticles (NPs) embedded in a-SiO 2 and subjected to SHII can undergo an intriguing shape transformation where once-spherical NPs become progressively more rodlike with the direction of elongation aligned along that of the incident ion. This phenomenon has been reported for several metals under a wide range of SHII conditions, with Refs. [7][8][9][10][11][12][13][14][15][16][17] citing selected examples. Freestanding metallic NPs irradiated under comparable conditions do not change shape, demonstrating the embedding a-SiO 2 matrix must have a role in the shape transformation process [8,17]. An unambiguous ...

show abstract

“…It is not reasonable to ascribe only the knocked-on displacements to the elongation of FePt particles. D'Orléans et al [11][12][13] recently reported that irradiation with 200 MeV 127 I ions up to 1 Â 10 18 ions/m 2 causes elongation of implanted Co nanoparticles in a SiO 2 layer along the beam direction. They have attributed the particle deformation to the thermal spike effects characteristic to the swift heavy ion irradiation.…”

Section: Nanostructure Change Due To Ion-irradiationmentioning

confidence: 99%

“…11) On the other hand, swift heavy ions with such higher energy as a few hundred MeV are known to deform metallic particles embedded in an oxide amorphous layer. [12][13][14] Thus ion-irradiation is expected as a tool for nano-structure modification of thin films.…”

Section: Introductionmentioning

confidence: 99%

Morphological Change in FePt Nanogranular Thin Films Induced by Irradiation with 2.4 MeV Cu<SUP>2+</SUP> Ions: Electron Tomography Observation

et al. 2006

View full text Add to dashboard Cite

Nanogranular thin films, in which FePt nannoparticles are dispersed in an amorphous 20 nm thick Al 2 O 3 layer, were irradiated with 2.4 MeV Cu 2þ ions up to 5 Â 10 19 ions/m 2 at room temperature. Electron tomography with a tilt series of bright-field transmission electron microscope images was employed to identify 3-dimensional structural changes due to irradiation. Electron tomography images have clearly revealed that the irradiation with 2.4 MeV Cu 2þ ions causes anisotropic deformation of FePt nanoparticles with elongation along the direction of ions trajectory and slight shrinkage in the perpendicular directions. Ion-irradiation results in disordering in FePt, but post-irradiation annealing at 923 K for 1 h (3.6 ks) leads to re-ordering without significant coarsening and shape change of FePt particles. It has been demonstrated that electron tomography is a quite useful technique for characterization of shape and dispersion of metallic nanoparticles embedded in an amorphous oxide film.

show abstract

Publisher’s Note: Anisotropy of Co nanoparticles induced by swift heavy ions [Phys. Rev. B67, 220101 (2003)]

Cited by 15 publications

References 0 publications

Observation of a Universal Aggregation Mechanism and a Possible Phase Transition in Au Sputtered by Swift Heavy Ions

Observation of a Universal Aggregation Mechanism and a Possible Phase Transition in Au Sputtered by Swift Heavy Ions

Role of Thermodynamics in the Shape Transformation of Embedded Metal Nanoparticles Induced by Swift Heavy-Ion Irradiation

Morphological Change in FePt Nanogranular Thin Films Induced by Irradiation with 2.4 MeV Cu<SUP>2+</SUP> Ions: Electron Tomography Observation

Contact Info

Product

Resources

About