Ion beam induced modification of nanolayers containing vanadium and silica

Layers of vanadium monoxide (VO) and pure silica were alternately deposited on a silica substrate. Similarly, layers of V2O3 and pure silica were alternately deposited on a silica substrate. The interfaces between the codeposited layers and pure silica layers were at no time exposed to air. Each sample was bombarded by 5.0 MeV Si beam at fluences between 1015 and 1017 ions/cm2 at room temperature. Optical properties were measured using Optical Absorption Photospectrometry (OAP). The elemental distribution was measured using Rutherford Backscattering Spectrometry (RBS) at each step of Si bombardment. A different piece of each layered sample was annealed at temperatures between 100 and 1100 °C steps, for 1 h in argon environment. OAP and RBS were observed after each temperature. The dramatic apperance of an optical absortion resonance at 410 nm after heat treatment to 600 °C indicates that vanadium nanocrystals form in silica at that temperature. An ion bomdarment induced mixing coefficient is derived and experimentally evaluated for vanadium in silica. It is observed to increase with the accumulated fluence and multilayered samples.