Amorphous to Amorphous Phase Transformation in Boron-Rich Amorphous Silicon Borides: An Ab Initio Study

Abstract

This study employs a constant-pressure ab initio approach to investigate the high-pressure behavior of five distinct boron-rich amorphous silicon borides. A unique amorphous-to-amorphous phase transition is exposed, providing insights into the structural resilience of these materials under extreme conditions. Our results reveal a gradual increase in the coordination number of both B and Si atoms under pressure, with subsequent densification upon pressure release. Yet the recovered amorphous phases closely resemble the uncompressed states, highlighting the reversibility of these phase changes. Significant structural modifications around Si atoms are observed, emphasizing their pivotal role in the observed phase transitions. Additionally, pressure-induced metallization is witnessed in these materials, indicating their distinctive electronic behavior under high pressure. This work significantly contributes to a deeper understanding of the high-pressure behavior of boron-rich amorphous silicon borides and opens avenues for exploring their potential applications in fields requiring exceptional structural stability and unique pressure-dependent properties.