AI 中文总结
研究以FeNi等Cantor-Wu合金为对象，通过飞秒与纳秒激光烧蚀实验结合第一性原理计算，揭示合金电子输运性质及磁相对其的依赖关系，发现单脉冲烧蚀阈值可作为非接触式灵敏探针。
AI 中文摘要
针对选定的等原子Cantor-Wu合金——FeNi、CoNi、CrFeNi、CrCoNi和CrMnFeCoNi，测量其在飞秒与纳秒脉冲持续时间下的单脉冲激光烧蚀阈值，并通过电子结构、电子-声子耦合及电子热导率的第一性原理计算对结果进行解释。合金合成、烧蚀实验及理论计算均在同一组样品上一致开展。从FeNi到含Cr合金，吸收的飞秒阈值呈系统性下降，降幅最高达36%，该趋势无法通过反射率变化解释。基于双温度模型，利用取自自旋无序相的所有参数，将阈值与电子热导率、电子-声子耦合进行标度，可复现测得的阈值层级。纳秒阈值则探测沿加热路径平均的热平衡电导率。CoNi作为明显的异常值，其室温输运性质对两种脉冲持续时间下阈值的预测均偏高，最高达两倍，该异常可通过其铁磁序丧失时电导率的骤降得到定量解释。由此可见，单脉冲烧蚀阈值可作为灵敏、非接触式探针，用于探究成分复杂合金的电子输运及其与磁相的依赖关系。
英文摘要
Single-pulse laser ablation thresholds of selected equiatomic Cantor-Wu alloys - FeNi, CoNi, CrFeNi, CrCoNi, and CrMnFeCoNi - are measured for femtosecond and nanosecond pulse durations and interpreted through first-principles calculations of the electronic structure, the electron-phonon coupling, and the electronic thermal conductivity. Alloy synthesis, ablation experiments, and theory are performed consistently on the same set of samples. The absorbed femtosecond thresholds decrease systematically by up to 36 % from FeNi to the Cr-containing alloys, a trend that reflectance variations cannot explain. Two-temperature-model scaling of the thresholds with the electronic thermal conductivity and the electron-phonon coupling, with all parameters taken from the spin-disordered phase, reproduces the measured hierarchy. The nanosecond thresholds instead probe the thermal equilibrium conductivity averaged along the heating path. The apparent outlier of CoNi, whose room-temperature transport over-predicts its thresholds by up to a factor of two for both pulse durations, is resolved quantitatively by the collapse of its conductivity upon loss of ferromagnetic order. Single-pulse ablation thresholds thereby emerge as sensitive, contact-free probes of electronic transport and of its magnetic-phase dependence in compositionally complex alloys.
