Irradiation Temperature Dependence of Shape Elongation of Metal Nanoparticles in Silica: Counterevidence to Ion Hammering Related Scenario

Quantum Beam Science

article

Hiroshi Amekura¹  Saif Ahmad Khan²  Pawan Kumar Kulriya²  Debdulal Kabiraj² 

[1] National Institute for Materials Science;Inter-University Accelerator Centre;School of Physical Sciences, Jawaharlal Nehru University

关键词: shape elongation;    metal nanoparticle;    swift heavy ion;    irradiation temperature dependence;    ion shaping;    optical linear dichroism spectroscopy;    silica glass;   

DOI  :  10.3390/qubs7020012

学科分类：环境科学（综合）

来源: mdpi

【 摘 要 】

Irradiation temperature (IT) dependence of the elongation efficiency of vanadium nanoparticles (NPs) in SiO2 was evaluated: The samples were irradiated with 120 MeV Ag9+ ions to a fluence of 1.0 × 1014 ions/cm2 each at ITs of 300, 433, 515, and 591 K, while the measurements were performed at room temperature. The vanadium was selected for the NP species because of the highest bulk m.p. of 1910 °C (2183 K) among all the species of the elemental metal NPs in which the shape elongation was observed. The highest m.p. could contribute negligible size changes of NPs against inevitable exposure to high temperatures for the IT dependence measurements. The elongation of V NPs was evaluated qualitatively by transmission electron microscopy (TEM) and quantitatively by optical linear dichroism (OLD) spectroscopy. The electron microscopy studies showed a pronounced elongation of NPs with ion irradiation at the elevated temperatures. The OLD signal was almost constant, or even slightly increased with increasing the IT from 300 to 591 K. This IT dependence provides a striking contrast to that of the ion hammering (IH) effect, which predicts a steep decrease with increasing IT. Combined with the other two counterevidence previously reported, the IH-related effect is excluded from the origin of the shape elongation of metal NPs in SiO2.

【 授权许可】

CC BY