arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.01471cond-mat.mtrl-sci
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电子辐照铜铁矿金属中缺陷的可控引入

Controlled introduction of defects to delafossite metals by electron irradiation

V. Sunko, P. H. McGuinness, C. S. Chang, E. Zhakina, S. Khim, C. E. Dreyer, M. Konczykowski, M. König, D. A. Muller, A. P. Mackenzie

摘要:

铜铁矿金属PdCoO $_{2}$、PtCoO $_{2}$和PdCrO $_{2}$是已知的最高导电性材料,在最好的生长单晶中具有数十微米的低温平均自由程。一个关键的问题是,这些非常低的电阻散射率是否是由于电子结构的特殊特征而导致的强烈抑制的背散射,或者是晶体完美性的高度不寻常水平的结果。我们报告的实验结果,其中使用高能电子辐照引入点无序的Pd和Pt层中的导电发生。我们得到的横截面形成的弗伦克尔对的绝对单位,并交叉检查我们的分析与第一性原理计算的相关原子位移能量。我们观察到的电阻率的增加,是线性的缺陷密度的斜率一致的散射在单一的限制。我们的研究结果使我们能够推断,生长的晶体含有极低水平的面内缺陷的约$0.001\%$。这证实了晶体的完美性是实现长平均自由程的最重要因素,并强调了这些铜铁矿金属与绝大多数其他多组分氧化物和合金相比是多么的不寻常。我们讨论了我们的研究结果对未来材料研究的影响。

英文摘要:

The delafossite metals PdCoO$_{2}$, PtCoO$_{2}$ and PdCrO$_{2}$ are among the highest conductivity materials known, with low temperature mean free paths of tens of microns in the best as-grown single crystals. A key question is whether these very low resistive scattering rates result from strongly suppressed backscattering due to special features of the electronic structure, or are a consequence of highly unusual levels of crystalline perfection. We report the results of experiments in which high energy electron irradiation was used to introduce point disorder to the Pd and Pt layers in which the conduction occurs. We obtain the cross-section for formation of Frenkel pairs in absolute units, and cross-check our analysis with first principles calculations of the relevant atomic displacement energies. We observe an increase of resistivity that is linear in defect density with a slope consistent with scattering in the unitary limit. Our results enable us to deduce that the as-grown crystals contain extremely low levels of in-plane defects of approximately $0.001\%$. This confirms that crystalline perfection is the most important factor in realizing the long mean free paths, and highlights how unusual these delafossite metals are in comparison with the vast majority of other multi-component oxides and alloys. We discuss the implications of our findings for future materials research.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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