论文标题
空缺驱动的非立我们的本地结构和磁各向异性剪裁以fe $ _x $ o-o-fe $ _ {3-Δ} $ o $ _4 $ nanocrystals
Vacancy-driven non-cubic local structure and magnetic anisotropy tailoring in Fe$_x$O-Fe$_{3-δ}$O$_4$ nanocrystals
论文作者
论文摘要
与散装材料相反，纳米级晶体生长受大小和形状依赖性特性的严重影响。但是，破译化学计量学在混合价元素的领域中如何起作用来控制物理特性，这是一项挑战，尤其是在复杂键合所暗示的结构缺陷的短期和远距离订购时。在这里，发现溶解剂氧化铁晶岩（NCS）的溶液生长的氧化铁矿系统可转换为缺陷的缺陷岩石盐和铁旋转型子层，但达到了令人惊讶的四扭曲的局部结构。化学均匀NC中的阳离子空位被描绘为调整潜在特性的参数。这些晶格缺陷被证明会产生局部交换 - 扭转拷贝场，从而增强纳米颗粒的磁化并克服有限尺寸效应的影响。亚临界大小NC中原子尺度缺陷控制的概念渴望成为量身定制特性的途径，其性能改善了无缺陷NC的高温加热。
In contrast to bulk materials, nanoscale crystal growth is critically influenced by size- and shape-dependent properties. However, it is challenging to decipher how stoichiometry, in the realm of mixed-valence elements, can act to control physical properties, especially when complex bonding is implicated by short and long-range ordering of structural defects. Here, solution-grown iron-oxide nanocrystals (NCs) of the pilot wustite system are found to convert into iron-deficient rock-salt and ferro-spinel sub-domains, but attain a surprising tetragonally distorted local structure. Cationic vacancies within chemically uniform NCs are portrayed as the parameter to tweak the underlying properties. These lattice imperfections are shown to produce local exchange-anisotropy fields that reinforce the nanoparticles magnetization and overcome the influence of finite-size effects. The concept of atomic-scale defect control in subcritical size NCs, aspires to become a pathway to tailor-made properties with improved performance for hyperthermia heating over defect-free NCs.
