Nanoscale potential fluctuations in nonstoichiometrics tantalum oxide.

The atomic and electronic structure of nonstoichiometric amorphous tantalum oxide (TaO ) films of different composition has been investigated by means of electron microscopy, x-ray photoelectron spectroscopy, Raman and infrared spectroscopy. The dispersion of the absorption coefficient and refraction index has been studied by spectral ellipsometry. The optical spectra were interpreted using the results of a quantum-chemical simulation for crystalline orthorhombic TaO .