Phase relationship in the TiO2–Nd2O3 pseudo-binary system

Abstract

Phase equilibria in the TiO2–Nd2O3 system have been experimentally investigated via X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Four compounds Nd2Ti2O7, Nd2TiO5, Nd2Ti3O9 and Nd4Ti9O24 were confirmed to exist. The literature reported Nd2Ti4O11 was proved to be the same compound as Nd4Ti9O24, and the reported phase transformation of Nd2Ti4O11 from α structure to β at 1373K was not detected. All the phase diagram data from both the literatures and the present work were critically reviewed and taken into account during the thermodynamic optimization of the TiO2–Nd2O3 system. A set of consistent thermodynamic parameters, which can explain most of the experimental data of the TiO2–Nd2O3 system, was achieved. The calculated phase diagram of the TiO2–Nd2O3 system was provided.