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A research team from the University of Chinese Academy of Sciences has revealed the failure mechanism of diamond under extreme electrical fields through in situ experiments and molecular dynamics simulations. The study, in Cell Reports Â鶹ÒùÔºical Science, provides critical insights for the design of robust diamond devices.

Diamond is known for its exceptional physical properties, including ultra-high breakdown field strength and thermal conductivity, making it a promising material for high-frequency and high-power electronics. However, its failure process under extreme electrical fields has remained poorly understood before now.

Led by Profs. Yan Qingbo and Chen Guangchao, the researchers used an in situ transmission electron microscopy (TEM) method to observe the breakdown process in real time. They found that diamond failure begins preferentially along the (111) crystal plane due to stress-induced lattice distortion and subsequent amorphization, rather than transforming into graphite.

The researchers also used molecular dynamics (MD) simulations to confirm that the (111) surface is more susceptible to thermal collapse at high temperatures, which aligns perfectly with their experimental observations. This study clarifies the crystallographic dependency of diamond's electrical failure and suggests that using (100)- or (110)-oriented diamond exposed substrates could significantly enhance device durability.

This study deepens our understanding of diamond behavior under extreme conditions and opens new pathways for more durable diamond-based electronic devices.

The researchers expected these findings to influence the design and material selection of diamond-based devices in fields such as quantum computing, high-power transistors, and ultraviolet lasers.