Anisotropic deformation of colloidal particles under 4 MeV Cu ions irradiation

Abstract Anisotropic deformation of colloidal particles was investigated under ion irradiation with 4 MeV Cu ions. In this study, 0.5 μ m-diameter silica particles, Au-silica core–shell and 15 nm-diameter Au colloids embedding in a planar Si/SiO 2 matrix were irradiated ions at room temperature normal incidence. beam causes dramatic anisotropic deformation; expands perpendicular to the contracts parallel, whereas cores elongate. SiO anisotropically transformed from spherical elongated nanorods by irradiating them The degree anisotropy varied flux. Upon embedded colloids, dark-field light scattering experiments revealed distinct color shift yellow, which indicates surface plasmon resonance. A resonance measurement reveals bands are split along arrays colloids. Our measurements have shifts that extend into near-infrared spectrum as much 50 nm.