Study of chromium states in silica glass implanted with Cr+ ions to high fluences

Abstract The implantation of transition metal ions in glasses can lead to the formation of nanometer-sized colloidal particles embedded in a thin surface layer. In the present work, silica glasses implanted with Cr+ at energy E=200 keV, for fluences larger than 1017 ions/cm2 were studied by electron paramagnetic resonance, X-ray photoelectron and X-ray-excited Auger electron spectroscopies, visible optical spectroscopy and scanning transmission electron microscopy (TEM). It is shown that Cr is present in silica glass as isolated Cr3+ ions as well as chromium oxides (antiferromagnetic Cr2O3 and ferromagnetic CrO2) and chromium silicides. TEM indicates the presence of almost spherical colloidal particles about 10 nm in diameter.