The semiconductor-type EuMnSb single crystal with an orthorhombic structure (space group , No.62) was synthesized using the Sn-flux method, and its physical properties were systematically investigated by magnetization, specific heat, and resistivity measurements. The magnetic and specific heat features reveal two successive antiferromagnetic (AFM) transitions exist separately at ∼ 21 K and ∼ 9 K, which have different responses to external magnetic field, and magnetic anisotropy is enhanced as the temperature is below . When the magnetic field is about 1.7 T and parallels the -axis of the EuMnSb crystal, a spin-flop transition of the AFM order appears. Electronic transport measurements show that the single crystal of EuMnSb manifests semiconductor characteristic and magnetic field-induced semiconductor-to-metal transitions. In addition, we observe a colossal negative magnetoresistance for both in-plane and out-of-plane resistivity and two-fold period anisotropic magnetoresistance. Combining magnetic susceptibility, specific heat capacity and resistivity properties, we present a phase diagram which can be divided into AFM semiconductor, paramagnetic semiconductor and paramagnetic metal. These unique properties indicate that EuMnSb can provide a platform for investigating the interplay between magnetic order, and charge transport.

中文翻译：

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半导体型 EuMnSb2 的磁性、磁输运特性及其与磁场的相关性

采用Sn-flux法合成了具有斜方结构（空间群，No.62）的半导体型EuMnSb单晶，并通过磁化强度、比热和电阻率测量系统地研究了其物理性质。磁性和比热特征表明，在~ 21 K和~ 9 K温度下分别存在两个连续的反铁磁（AFM）转变，它们对外部磁场有不同的响应，并且随着温度低于 ，磁各向异性增强。当磁场约为1.7 T并平行于EuMnSb晶体的-轴时，出现AFM级的自旋翻转跃迁。电子输运测量表明，EuMnSb 单晶表现出半导体特性和磁场诱导的半导体到金属的转变。此外，我们观察到面内和面外电阻率均存在巨大的负磁阻，以及两倍周期各向异性磁阻。结合磁化率、比热容和电阻率特性，我们提出了可分为AFM半导体、顺磁半导体和顺磁金属的相图。这些独特的性质表明 EuMnSb 可以为研究磁序和电荷传输之间的相互作用提供一个平台。