...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Experimental And Atomistic Modeling Study Of Ion Irradiation Damage In Thin Crystalsrnof The Tio_2 Polymorphs
【24h】

Experimental And Atomistic Modeling Study Of Ion Irradiation Damage In Thin Crystalsrnof The Tio_2 Polymorphs

机译：Tio_2多晶型物在薄晶体中离子辐照损伤的实验和原子建模研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Thin crystals of rutile, brookite, and anatase were irradiated in situ in the intermediate voltage electron microscope (IVEM-Tandem Facility) at Argonne National Laboratory using 1.0 MeV Kr ions at a temperature of 50 K. Determination of the critical amorphization rluence has revealed a large difference in the radiation tolerance. Synthetic rutile remained crystalline up to a rluence of 5 × 10~(15) ions cm~(-2) and did not show convincing evidence for the onset of amorphization at this fluence level. Natural brookite and anatase, on the other hand, became amorphous at 8.1 ± 1.8 × 10~(14) and 2.3 ± 0.2 × 10~(14) ions cm~(-2), respectively. These results correlate with the number of shared edges, the degree of octahedral distortion, and the volume properties of polymorphs, and we show that the distortion and the volume are intimately linked through interatomic forces in the octahedral framework. The static and dynamic defect calculations indicate that the radiation tolerance of rutile is related, at least in part, to low energy migration pathways for both O and Ti. In order to gain further insight into the problem, we performed molecular dynamics (MD) simulations of small thermal spikes for each polymorph. These simulations are in qualitative agreement with the experiments, with the thermal spikes showing the same relative recovery behavior between the rutile, the brookite, and the anatase structures. The examination of previous MD simulations of TiO_2 glasses and experimental work on synthetic TiO_2 materials produced at low temperature provides a conceptual model for the structure of amorphous TiO_2 produced by ion irradiation of the crystalline polymorphs.
机译：金红石，板钛矿和锐钛矿的薄晶体在Argonne国家实验室的中压电子显微镜（IVEM-串联装置）中使用1.0 MeV Kr离子在50 K的温度下进行了原位辐照。辐射耐受性差异很大。合成金红石在5×10〜（15）离子cm〜（-2）的辉度下仍保持结晶状态，并且没有显示令人信服的证据表明在此浓度水平下会发生非晶化。另一方面，天然板钛矿和锐钛矿分别在8.1±1.8×10〜（14）和2.3±0.2×10〜（14）离子cm〜（-2）时变成无定形。这些结果与共享边的数量，八面体变形的程度以及多晶型物的体积特性相关，并且我们表明，变形和体积通过八面体框架中的原子间力紧密相连。静态和动态缺陷计算表明，金红石的辐射耐受性至少部分与O和Ti的低能量迁移路径有关。为了进一步了解该问题，我们对每个多晶型物进行了小热峰的分子动力学（MD）模拟。这些模拟与实验定性一致，热峰表明金红石，板钛矿和锐钛矿结构之间的相对恢复行为相同。先前对TiO_2玻璃的MD模拟的研究以及在低温下生产的合成TiO_2材料上的实验工作的研究，为通过结晶多晶型物的离子辐照生产的非晶TiO_2的结构提供了概念模型。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号