发表机构
AGH University of Krakow; Institute of Nuclear Physics, Polish Academy of Sciences; European Synchrotron Radiation Facility; Univ. Grenoble Alpes; Institut Néel, CNRS and Univ. Grenoble Alpes（克拉科夫AGH科技大学; 波兰科学院核物理研究所; 欧洲同步辐射装置; 格勒诺布尔阿尔卑斯大学; 法国国家科学研究中心和格勒诺布尔阿尔卑斯大学奈尔研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过DFXM和交流磁化率测量发现，磁铁矿中由单轴压缩产生的扩展线状缺陷和残余应变场不会可测量地影响Verwey相变温度及其锐度，与点缺陷的强烈抑制效应形成对比，揭示了不同缺陷类型对电子相变的不同影响。
AI 中文摘要
磁铁矿中的Verwey相变是一个基准的电子驱动相变，对晶格缺陷和外部扰动高度敏感。已知掺杂、氧化学计量偏离以及辐照诱导的点缺陷会降低Verwey相变温度$T_{\rm V}$。相比之下，由单轴应力产生的残余应变场和扩展缺陷结构的作用在很大程度上尚未被探索。在此，我们结合暗场X射线显微镜（DFXM）和交流磁化率测量，以确定在单轴压缩和卸载后，应变诱导缺陷如何影响化学计量单晶磁铁矿中的Verwey相变。DFXM测量在沿相同$[011]$方向压缩的两个样品上进行：加载至$200~\mathrm{MPa}$产生了稳定的线状缺陷和残余应变场，而加载超过断裂阈值则产生了更密集的缺陷网络和机械断裂。为测试不同加载几何的影响，我们还测量了沿$[001]$压缩断裂样品的交流磁化率。实空间DFXM成像、晶格取向映射和残余应变映射显示压缩后存在显著的残余结构无序。然而，在任何压缩或断裂样品中，相变温度$T_{\rm V}$和相变锐度均未发生可测量的变化。这一行为与点状无序对$T_{\rm V}$的强烈抑制形成对比。我们的结果表明，由塑性变形产生的扩展线状缺陷和残余应变场不会可测量地扰动负责Verwey相变的宏观电子有序，从而区分了点缺陷与磁铁矿中扩展滑移相关缺陷的作用。
英文摘要
The Verwey transition in magnetite is a benchmark electronically driven phase transition that is highly sensitive to lattice imperfections and external perturbations. Doping, deviations from oxygen stoichiometry, and irradiation-induced point defects are known to lower the Verwey transition temperature, $T_{\rm V}$. By contrast, the role of remanent strain fields and extended defect structures generated by uniaxial stress has remained largely unexplored. Here we combine dark-field x-ray microscopy (DFXM) and ac magnetic susceptibility to determine how strain-induced defects affect the Verwey transition in stoichiometric single-crystalline magnetite after uniaxial compression and unloading. The DFXM measurements were performed on two samples compressed along the same $[011]$ direction: loading to $200~\mathrm{MPa}$ generated stable line-like defects and remanent strain fields, whereas loading beyond the fracture threshold produced denser defect networks and mechanical fracture. To test the effect of a different loading geometry, we also measured the ac susceptibility of a sample fractured by compression along $[001]$. Real-space DFXM imaging, lattice-orientation mapping, and residual strain mapping show substantial remanent structural disorder after compression. Nevertheless, neither the transition temperature $T_{\rm V}$ nor the sharpness of the transition changes measurably in any of the compressed or fractured samples. This behavior contrasts with the strong suppression of $T_{\rm V}$ by point-like disorder. Our results show that extended line-like defects and remanent strain fields produced by plastic deformation do not measurably perturb the macroscopic electronic ordering responsible for the Verwey transition, thereby distinguishing the effects of point defects from those of extended slip-related defects in magnetite.
