论文标题
单晶kco $ _2 $的物理特性和电子结构为$ _2 $
Physical properties and electronic structure of single-crystal KCo$_2$As$_2$
论文作者
论文摘要
我们提出了一种产生高质量KCO2AS2晶体的方法，在空气中稳定，适合各种测量。 X射线衍射，磁化率，电运输和热容量测量值确认了至少2 K的高质量和远程磁性顺序。接近0.25 $μΩ$ 〜cm的残留电阻率值代表了高质量和低杂质含量，以及SOMMERFELD $γ$ = 7.3 mj/mol k $ k $^2 $^2 $^2 $^2 $^2 $ feepies corfore cormer cormer。与HALL效应测量值一起，角度分辨光发射实验揭示了一个费米表面，该表面由布里鲁因区域的中心和角落组成，与理论预测一致，与其他PNICT类型的混合载体类型与THCR2SI2结构相一致。在14〜T时，具有200 \％的较大的线性磁倍率，以及观察到的线性和双曲线而不是抛物线的线性磁性，带状分散体是这种金属化合物的异常特征，可能表明基本行为更复杂。
We present a method for producing high quality KCo2As2 crystals, stable in air and suitable for a variety of measurements. X-ray diffraction, magnetic susceptibility, electrical transport and heat capacity measurements confirm the high quality and an absence of long range magnetic order down to at least 2 K. Residual resistivity values approaching 0.25 $μΩ$~cm are representative of the high quality and low impurity content, and a Sommerfeld coefficient $γ$ = 7.3 mJ/mol K$^2$ signifies weaker correlations than the Fe-based counterparts. Together with Hall effect measurements, angle-resolved photoemission experiments reveal a Fermi surface consisting of electron pockets at the center and corner of the Brillouin zone, in line with theoretical predictions and in contrast to the mixed carrier types of other pnictides with the ThCr2Si2 structure. A large, linear magnetoresistance of 200\% at 14~T, together with an observed linear and hyperbolic, rather than parabolic, band dispersions are unusual characteristics of this metallic compound and may indicate more complex underlying behavior.
