Controlled anisotropic deformation of Ag nanoparticles by Si ion irradiation

The shape and alignment of silver nanoparticles embedded in a glass matrix is controlled using silicon ion irradiation. Symmetric silver nanoparticles are transformed into anisotropic particles whose larger axis is along the ion beam. Upon irradiation, the surface plasmon resonance of symmetric particles splits into two resonances whose separation depends on the fluence of the ion irradiation. Simulations of the optical absorbance unambiguously show that the anisotropy is caused by the deformation and alignment of the nanoparticles, and that both properties are controlled with the irradiation fluence.