Investigation of phase transition employing strain mapping in TT- and T-Nb2O5 obtained by HRTEM micrographs

This work aimed to study the crystalline structure of TT-,T-phases of Nb2O5 nanoparticles through XRD, Rietveld refinement, and HRTEM, using geometric phase analysis (GPA). The results show the presence of distorted NbO6 and NbO7 polyhedral, producing strain effects, mainly in the plane boundaries and along the b-c plane. XRD and HRTEM analyses show the TT -> T transition at 700 degrees C, with increased particle size and increased strain in the boundaries between nanoparticles. The sample calcinated at 700 degrees C presents segregation of the TT-(001), (100), and T-(130) planes, where the strain effect is more relevant along the [100] zone axis and between phases.

Automated summary

This study aimed to investigate the crystalline structure of TT- and T-phases of Nb2O5 nanoparticles using XRD, Rietveld refinement, and HRTEM with GPA. The results revealed the presence of distorted NbO6 and NbO7 polyhedral, resulting in strain effects primarily in the plane boundaries and along the b-c plane. XRD and HRTEM analyses demonstrated the TT -> T transition at 700 degrees C, leading to increased particle size and strain in the boundaries between nanoparticles.