High-density amorphous phase of CdO

Abstract

An amorphous CdO model is densified up to a theoretical pressure of 200 GPa. A continues phase transformation from a low-density amorphous (LDA) phase to a high-density amorphous (HDA) phase is observed through the simulation. Associated with the phase transformation, the average coordination raises progressively from similar to 5.5 to similar to 7.0. The sevenfold coordination is the most abundant motifs in the HDA state. Therefore its short-range order differs principally from that of the known CdO crystals. Upon pressure release, an amorphous state being intermediate between the LDA structure and the HDA phase is recovered with a mean coordination number of 5.9. (C) 2017 Elsevier B.V. All rights reserved.