Configurations, energies, and thermodynamics of the neutral MgH complex in GaN
Configurations, energies, and thermodynamics of the neutral MgH complex in GaN
复制标题
GaN 中中性 MgH 配合物的构型、能量和热力学
DOI：
10.1063/1.1610232
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发表时间：
2003
影响因子：
3.2
通讯作者：
S. Myers
中科院分区：
文献类型：
--
作者：
A. F. Wright;S. Myers
利用密度泛函理论和广义梯度近似的交换和相关性，确定了纤锌矿GaN中中性MgH络合物的局部能量最小值对应的原子构型。MgH的结合能，H的本地模式的振动频率，和配置简并的六个最低能量的配置，沿着与相应的结果孤立的H+，计算平衡H态人口在Mg掺杂的GaN作为温度的函数。当Mg浓度为1×1019/cm ~ 3，H/Mg浓度比为0.99时，室温下MgH为主要的H物种，T = 550 °C时，H+为主要的H物种。 在MgH状态，一个被发现在所有温度下占主导地位。主要构型由位于取代Mg的N邻位的反键位的H组成，Mg-N键和N-H键几乎对齐，N-H键与c轴成θ 109°角取向。的H拉伸模式频率。
Atomic configurations corresponding to local-energy minima for the neutral MgH complex in wurtzite GaN are identified using density-functional theory and the generalized-gradient approximation for exchange and correlation. MgH binding energies, H local-mode vibration frequencies, and configurational degeneracies for the six lowest-energy configurations are used, along with corresponding results for isolated H+, to compute equilibrium H state populations in Mg-doped GaN as a function of temperature. For a Mg concentration of 1×1019/cm3 and a H/Mg concentration ratio of 0.99, MgH is found to be the majority H species at room temperature with isolated H+ becoming the majority species at T≈550 °C. Among the MgH states, one is found to dominate at all temperatures. The dominant configuration consists of H at an antibonding site of a N neighbor of the substitutional Mg, with the Mg–N and N–H bonds nearly aligned and the N–H bond oriented at an angle of ∼109° with the c axis. The H stretch-mode frequency of the ...