论文标题
KCA $ {_ 2} $ fe $ {_ 4} $ as $ {_ 4} $ f $ {_ 2}
Anisotropic physical properties and large critical current density in KCa${_2}$Fe${_4}$As${_4}$F${_2}$ single crystal
论文作者
论文摘要
我们介绍了对电阻率，霍尔系数，磁光成像，磁化和茎分析的系统研究，对KCA $ {_ 2} $ fe $ {_ 4} $作为$ {_ 4} $ f $ {_ 2} $ {_ 2} $。尖锐的磁性过渡和磁光成像揭示了单晶和涡流的突出豆样穿透性的同质性。 $ {ρ_C /ρ_{ab}} $> 100的大型电阻率各向异性和类似半导体的$ {ρ_C} $表明电子状态是准二维。霍尔效果测量表明，$ {_ 4} $ a $ {_ 4} $ {_ 4} $ f $ {_ 2} $是一个具有孔作为主要载体的多型系统。与其他基于铁的超导体相比，磁化测量结果明显更大的j $ _c $，根据磁场的方向，其值不同。这些J $ _C $特征的起源是根据使用STEM的微观结构观察来讨论的。此外，以重型离子辐照的方式证明了$ {_ 4} $的j $ _c $ in KCA $ {_ 2} $ fe $ {_ 4} $作为$ {_ 4} $ f $ {_ 2} $。
We present a systematic study of electrical resistivity, Hall coefficient, magneto-optical imaging, magnetization, and STEM analyses of KCa${_2}$Fe${_4}$As${_4}$F${_2}$ single crystals. Sharp diamagnetic transition and magneto-optical imaging reveal homogeneity of single crystal and prominent Bean-like penetrations of vortices. Large anisotropy of electrical resistivity, with ${ρ_c / ρ_{ab}}$ > 100, and semiconductor-like ${ρ_c}$ suggest that the electronic state is quasi two-dimensional. Hall effect measurements indicate that KCa${_2}$Fe${_4}$As${_4}$F${_2}$ is a multiband system with holes as main carriers. Magnetization measurements reveal significantly larger J$_c$ compared with that in other iron-based superconductors with different values of J$_c$ depending on the direction of magnetic field. Origin of these J$_c$ characteristics is discussed based on microstructural observations using STEM. In addition, further enhancement of J$_c$ in KCa${_2}$Fe${_4}$As${_4}$F${_2}$ for future application is demonstrated in terms of heavy-ion irradiation.
