标题： 在Zintl相Eu$_{11}$Zn$_6$As$_{12}$中的异常磁性和输运特性 显示英文标题

标题： Unusual magnetic and transport properties in the Zintl phase Eu$_{11}$Zn$_6$As$_{12}$

摘要： 窄带隙稀土Zintl相由于其多样的晶体结构、复杂的磁性性质和可调节的输运行为，经常表现出迷人的物理现象。 这里我们报告了一种含铕的Zintl砷化物的合成，以及其磁性、热力学和输运性质， Eu$_{11}$Zn$_6$As$_{12}$，它由无限的铕阳离子链和由顶点共享的ZnAs$_4$四面体构成的阴离子框架组成。 Eu$_{11}$Zn$_6$As$_{12}$由于离散的阴离子片段介导的复杂交换相互作用而表现出复杂的磁性行为。 在22 K（$T_\mathrm{N}$）和9 K（$T^*$）处的两个长程磁性转变，以及在约29 K（$T_\mathrm{F}$）处异常强烈的铁磁涨落，由磁化率、比热和电阻率测量结果所示。 此外，Eu$_{11}$Zn$_6$As$_{12}$表现出金属行为，这是由于轻微的Eu空位掺杂产生的空穴载流子或Eu$^{2+}$和Eu$^{3+}$的混合价态所致。 在$T_\mathrm{N}$附近出现明显的电阻率峰，该峰在施加磁场后迅速被抑制，导致显著的负磁阻效应。 在5 K以下观察到电阻率滞回现象，这是由一小的净铁磁成分引起的。 我们的研究展示了Eu$_{11}$Zn$_6$As$_{12}$的独特的磁性和输运特性，进一步的实验是必要的以阐明这些新奇行为的起源。 此外，我们的研究结果表明，基于Eu的Zintl相是研究磁性与电荷输运之间相互作用的肥沃土壤。 显示英文摘要

摘要： Narrow-gap rare-earth Zintl phases frequently exhibit fascinating physical phenomena due to their various crystal structures, complex magnetic properties, and tunable transport behaviors. Here we report the synthesis, magnetic, thermodynamic, and transport properties of a Eu-containing Zintl arsenide, Eu$_{11}$Zn$_6$As$_{12}$, which consists of infinite chains of Eu cations and anionic frameworks constructed from corner-sharing ZnAs$_4$ tetrahedra. Eu$_{11}$Zn$_6$As$_{12}$ exhibits complicated magnetic behavior owing to intricate exchange interactions mediated by the discrete anionic fragments. Two long-range magnetic transitions at 22 K ($T_\mathrm{N}$) and 9 K ($T^*$), as well as exceptionally strong ferromagnetic fluctuations around 29 K ($T_\mathrm{F}$), are indicated by the susceptibility, heat capacity and resistivity measurements. Besides, Eu$_{11}$Zn$_6$As$_{12}$ displays metallic behavior, attributable to the hole carriers doped by slight Eu vacancies or the mixed valence of Eu$^{2+}$ and Eu$^{3+}$. A prominent resistivity peak occurs around $T_\mathrm{N}$, which is rapidly suppressed by the applied field, leading to a prominent negative magnetoresistance effect. A resistivity hysteresis is observed below 5 K, caused by a small net ferromagnetic component. Our study presents the distinct magnetic and transport properties of Eu$_{11}$Zn$_6$As$_{12}$, and further experiments are required to elucidate the origin of these novel behaviors. Moreover, our findings demonstrate that Eu-based Zintl phases are a fertile ground to study the interplay between magnetism and charge transport.