Amorphous to crystalline transformation in Ta2O5 studied by Raman spectroscopy

Many of the interesting properties that make Ta 2 O 5 a strategic material for current and future applications in chemistry, microelectronics and optics, depend on its structural characteristics. In this work, we use Raman spectroscopy to probe structural modifications in amorphous Ta 2 O 5 coatings submitted to thermal annealing. On the basis of previous knowledge on the crystalline material, we perform Raman spectrum simulations in disordered and partially ordered Ta 2 O 5 from a phonon density of states. Calculated spectra are in good agreement with complex experimental spectra. Our original approach allows assignment of the vibrational features of the amorphous material, and quantitative interpretation of observed structural modifications in terms of ordering scales. In addition, it provides numerical indicators to analyse amorphous to crystalline phase transformation. Copyright © 2012 John Wiley & Sons, Ltd.