WikiEdge:ArXiv速递/2025-03-03

摘要

• 原文标题：Investigation of O interstitial diffusion in $β$-Ga$_2$O$_3$: direct approach via master diffusion equations
• 中文标题：$β$-Ga$_2$O$_3$中氧间隙扩散的研究：通过主扩散方程的直接方法
• 发布日期：2025-03-03 16:54:55+00:00
• 作者：Grace McKnight, Channyung Lee, Elif Ertekin
• 分类：cond-mat.mtrl-sci, physics.app-ph, physics.comp-ph
• 原文链接：http://arxiv.org/abs/2503.01735v1

原文摘要：Monoclinic $\beta$-Ga$_2$O$_3$, a promising wide band gap semiconducting material, exhibits complex, anisotropic diffusional characteristics and mass transport behavior as a results of its low symmetry crystal structure. From first-principles calculations combined with master diffusion equations, we determine three-dimensional diffusion tensors for neutral ($\text{O}_{\text{i}}^{0}$) and 2- charged oxygen interstitials ($\text{O}_{\text{i}}^{2-}$). Systematic exploration of the configurational space identifies stable configurations in these two dominant charge states and their corresponding formation energies. By connecting every pair of low-energy configurations considering both interstitial or interstitialcy hops, we construct three-dimensional diffusion networks and evaluate hopping barriers of all transition pathways in networks. Combining the collection of (i) defect configurations and their formation energies and (ii) the hopping barriers that link them, we construct and solve the master diffusion equations for $\text{O}_{\text{i}}^{0}$ and $\text{O}_{\text{i}}^{2-}$ separately through the Onsager approach, resulting in respective three-dimensional diffusion tensors D$_{\text{O}_{\text{i}}}^{0}$ and D$_{\text{O}_{\text{i}}}^{2-}$. Both $\text{O}_{\text{i}}^{0}$ and $\text{O}_{\text{i}}^{2-}$ present the fastest diffusion along the $b$-axis, demonstrating significant anisotropy. The predicted self-diffusivities along [100] and [$\overline{2}01$] align well with previously reported values from isotopically labeled oxygen tracer experiments, highlighting the reliability of the approach in capturing complex diffusion mechanisms.

中文摘要：单斜晶系的$\beta$-Ga$_2$O$_3$是一种有前景的宽带隙半导体材料，由于其低对称性的晶体结构，表现出复杂的各向异性扩散特性和质量传输行为。通过第一性原理计算结合主扩散方程，我们确定了中性氧间隙（$\text{O}_{\text{i}}^{0}$）和带2-电荷的氧间隙（$\text{O}_{\text{i}}^{2-}$）的三维扩散张量。通过对构型空间的系统探索，我们识别了这两种主要电荷态的稳定构型及其相应的形成能。通过考虑间隙或间隙跳跃，连接每一对低能构型，我们构建了三维扩散网络，并评估了网络中所有过渡路径的跳跃势垒。结合（i）缺陷构型及其形成能和（ii）连接它们的跳跃势垒，我们通过Onsager方法分别构建并求解了$\text{O}_{\text{i}}^{0}$和$\text{O}_{\text{i}}^{2-}$的主扩散方程，得到了相应的三维扩散张量D$_{\text{O}_{\text{i}}}^{0}$和D$_{\text{O}_{\text{i}}}^{2-}$。$\text{O}_{\text{i}}^{0}$和$\text{O}_{\text{i}}^{2-}$都表现出沿$b$轴的最快扩散，显示出显著的各向异性。沿[100]和[$\overline{2}01$]方向预测的自扩散系数与之前报道的同位素标记氧示踪实验值吻合良好，突出了该方法在捕捉复杂扩散机制方面的可靠性。