Solid-State Synthesis of Metastable Ytterbium (II) Oxide

Abstract

Due to its electron configuration (Xe) 4 f 14 6 s 2 , Ytterbium (Yb) could form divalent oxide, YbO. In this study, the solid-state synthesis of metastable YbO was investigated by the oxidation of Yb metal at normal pressure using two experimental conditions: 1) heat treatment of Yb metal under Ar gas atmosphere with metal carbonate as an oxygen source; and 2) heat treatment of Yb metal under the continuous gas flow condition using various gas atmospheres. Products were identified using the powder X-ray diffraction and scanning electron microscope. It was found that almost single phase YbO was obtained in the experimental condition 1) using the molar ratio of CaCO 3 /Yb = 0.4. Thermodynamic calculations suggested that the YbO formation be controlled not by thermodynamics but by kinetics, and further that the evaporation of Yb metal in the BN crucible played a key role for the formation of the me-ta-stable YbO.