Optical properties and microstructure of Ta

Tantalum pentoxide thin films are prepared by oblique angle electron beam evaporation. The influence of flux angle on the surface morphology and microstructure is investigated by scanning electron microscopy (SEM). The Ta₂O₅ thin films are anisotropic with highly orientated nanostructure of slanted columns. The porous microstructure of the as-deposited films results in the decrease of effective refractive index and packing density with increasing deposition angle. The aniso