| Jun 30, 2022 |
How to synthesize stable diamane at high pressure
(Nanowerk News) A research team led by Prof. WANG Xianlong from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences (CAS) has discovered a new method to improve the stability of diamane synthesized by-high pressure method. By introducing boron (B) and nitrogen (N) dopants into diamane, they found that the diamane's structure and electronic properties could be regulated.
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The results were published in Physical Review B ("Configuration stability and electronic properties of diamane with boron and nitrogen dopants").
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| Configurations of cubic diamane (a) and hexagonal diamane (b). (Image: NIU Caoping)
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Diamane is a two-dimensional (2D) single-layer diamond obtained by compressing bi-layer graphene to form interlayer sp3 bonds. With the characteristics of both graphene and diamond, it is expected to be a new 2D carbon material alongside graphene. However, diamane synthesized by high-pressure method is converted back to graphene after releasing pressure, and it cannot be maintained under ambient conditions.
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In this study, the researchers investigated the structural and electronic properties of different doped forms of B and N atoms in cubic and hexagonal diamane based on the first-principles methods.
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They found that the doping configuration reduced the formation energy of diamane, promoted the synthesis of diamane and enhanced the stability of diamane at ambient condition.
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They proposed an easiest mechanism to synthesize diamane experimentally by compressing bi-layer graphene with one layer doped with B atom and the other doped with N atom.
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Diamane doped with N atoms was easy to obtain experimentally because the formation energy of diamane was not sensitive to the distribution of N dopant. In addition, depending on the concentrations and distributions of B and N atoms, doped diamane had variable electronic structures (semiconductor, metal, superconductivity ~ 4 K), which could be applied to the field of 2D electronic devices.
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This work offers a new scheme to synthesize more stable and functional diamane.
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