Linear optical properties of a Ti-SiO2 nanoparticle composite

Abstract

We report the linear optical properties of a titanium nanoparticle composite formed by implantation of low energy Ti+ into single crystalline SiO2. A surface plasmon resonance (SPR) induced absorption band is found in the 650–850 nm wavelength range, i.e., in the visible (red) and near infrared regions, indicating the formation of Ti nanoparticles in the subsurface layer of the SiO2 matrix. The average size of the particles is ∼2.6 nm and the volume fraction is as low as 0.016. At the implantation energy of 9 keV and total dose of 3×1016 ions/cm2, the SPR absorption band becomes distinguishable only at temperatures greater than 600 °C and reaches its maximum at ∼800 °C (1/2Tm). Enhanced nucleation with nearly constant particle size with increasing temperature contributes to the increased SPR absorption intensity at temperatures ⩽800 °C. The SPR absorption intensity decreases significantly near 1000 °C (2/3Tm). A blueshift of the SPR absorption maximum with substrate temperature is also observed. The shape of the SPR absorption band and the difference between low and high energy implantations is discussed.