Exploration for oxygen diffusion during deoxidation process of terbium with 18O as isotope tracer

Abstract

Oxygen (O) is the most difficult kind of impurity to be removed from rare earth terbium (Tb), which seriously restricts the promotion of high purity rare earth metal quality. Study the law of oxygen removal during the purification process and clarify the influence and synergism of active substance are of great significance. Herein, isotopic tracer technique (using 18O) has been used to explore the oxygen diffusion process. Secondary ion probe mass spectrometer (SIMS) and Scanning Electron Microscope (SEM) investigated the occurrence state, migration trajectory and relative concentration gradient of oxygen in Tb. The diffusion coefficient as a function of depth and temperature can be simulated based on the experimental data, which is of great significance for the purification and corrosion prevention of Tb. X-ray photoelectron spectroscopy (XPS) clarified the variation of metal valence, indicating the bonding characteristics between O and Tb.