NaCl结构VC薄膜生长过程中原子迁移的第一性原理研究

First Principle Calculations of Atomic Transfer in Growth of NaCl-Structure VC Thin Film

为了解VC薄膜生长过程,通过第一性原理方法,对C(和V)原子在VC晶体表面和晶体内部的迁移情况进行了计算。结果显示,C(和V)的单原子在VC晶体表面格点位置具有最低的系统能量,此时,C原子的活动性仍较强,其迁移激活能仅为0.08 eV,而V原子由稳定的格点位置迁移则有较大阻力,激活能为2.48 eV;在VC晶体内部,C和V原子在(111)层面内迁移的激活能分别为3.34和4.30 eV,层间激活能分别为2.93和3.64 eV,表明它们在晶内的迁移极为困难。结合此结果,对VC薄膜的制备参数进行了讨论。

The transfer of V and C atomson thin-film surfaces and in bulk of the VC compound with NaCl-type structure was modeled and investigated by first principle calculations to gain an in-depth understanding of the growth of VC films. Thecalculated results show thaton the surface of VC film, C atomtransfers much easier than V atom does, and that in VC bulk, it is extremely difficult for both C and V atoms to transfer because of their high activation energies. For example, on V C surfaces, when it comes to a transfer from hcp-HL to fcc-HL, the activation energies of C and V atoms are 0.08 and 2.48 eV, respectively;however in VC （111） of the bulk,when it comes to the transfer in VC（ 111 ） plane,the activation energies of C and V atoms are 3.34 and 4.30 eV, respectively; and an inter-plane transfer requires an activation energy of 2.93 eV for C atom and 3.64 eV for V atom.