Undercooling driven growth of Q-carbon, diamond, and graphite
Undercooling driven growth of Q-carbon, diamond, and graphite
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DOI：
10.1557/mrc.2018.76
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发表时间：
2018-06-01
影响因子：
1.9
通讯作者：
Narayan, Jagdish
中科院分区：
文献类型：
--
作者：
Gupta, Siddharth;Sachan, Ritesh;Narayan, Jagdish
我们提供了有关通过纳秒激光熔化类金刚石碳（DLC）形成石墨、纳米金刚石和Q - 碳纳米复合材料时过冷度依赖性的见解。DLC薄膜在深度过冷状态下迅速熔化，随后淬火至室温。具有不同热性能的基底——硅和蓝宝石，被用于证明热导率较低的基底会阻碍热流，从而在实验上以及通过有限元模拟从理论上诱导出更大的过冷度。过冷度的增加有利于Q - 碳的形成。Q - 碳通过激光重熔和热丝化学气相沉积被用作金刚石生长的成核种子。
We provide insights pertaining the dependence of undercooling in the formation of graphite, nanodiamonds, and Q-carbon nanocomposites by nanosecond laser melting of diamond-like carbon (DLC). The DLC films are melted rapidly in a super-undercooled state and subsequently quenched to room temperature. Substrates exhibiting different thermal propertiessilicon and sapphire, are used to demonstrate that substrates with lower thermal conductivity trap heat flow, inducing larger undercooling, both experimentally and theoretically via finite element simulations. The increased undercooling facilitates the formation of Q-carbon. The Q-carbon is used as nucleation seeds for diamond growth via laser remelting and hot-filament chemical vapor deposition.