从DFT计算中对晶体缺陷α-石英的弹性机械性质和异性质的新见解
Lin Zhang1, Fen Jiao1, Wenqing Qin1
1School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
ACS omega
|November 29, 2023
概括
阿尔法石英晶体中的氧气空缺影响矿石研磨过程中的断裂力学. 了解这些缺陷揭示了对有色金属加工的晶体裂解机制的关键见解.
科学领域:
- 材料科学 材料科学 材料科学
- 矿物物理 矿物物理
- 计算化学计算化学
背景情况:
- 了解晶体裂变对于优化矿石矿石研磨工艺至关重要.
- 阿尔法石英是有色金属矿石中常见的矿物质,其断裂行为会影响加工效率.
- 晶体结构中的缺陷可以显著改变机械性能.
研究的目的:
- 为了研究在非铁金属矿石研磨过程中α-石英的裂变机制.
- 分析氧 (O) -空缺缺陷对α-石英晶体机械和电荷特性的影响.
- 阐明晶体缺陷,机械性能和裂变行为之间的关系.
主要方法:
- 用密度函数理论 (DFT) 的计算来研究α-石英.
- 在引入O-空缺缺陷之前和之后,使用弹性常量矩阵计算体积和剪切模块.
- 分析了映射表面,异构度指数 (AL,AU,AB) 和电子定位函数 (ELF).
主要成果:
- O-空缺缺陷增加了体积,剪切,模和波桑比率,同时降低了硬度.
- 散体与剪切模块 (B/G) 的比率表明,没有O空隙的晶体更容易破裂.
- 随着O空缺的出现,异性质显著增加,特别是散装异性质指数 (AB),其翻了一番.
- 裂纹在剪切应力下的 (011) 平面和正常应力下的 (111) 平面主导.
- O-空位减少了Si-Si键的长度,这表明新的共价键的形成.
结论:
- O-空缺缺陷从根本上改变了α-石英的机械和异性质性.
- 这些缺陷在不同的应力条件下影响主导的裂纹平面.
- 这些发现提供了一种系统的方法,通过集成的机械,异构和电子属性分析来理解晶体裂变行为.
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