Low-temperature phase transformation and phonon confinement in one-dimensional Ta₂O₅ nanorods

The variable-temperature X-ray diffraction results of the β(001), α(101) and α(103) lattice planes of one-dimensional Ta₂O₅ nanorods showed complex and polymorphic thermochromic phase transformations, which incorporate α-to-α (α–α), α–α–β and α–β phase transitions at elevated temperatures ranging from 80 to 300 K. The d-spacing expansions of the lattice planes can explain the thermochromic phase transformations between α- and β-phase crystals.