论文标题
金属到金属过渡和nd $ _4 $ ni $ _3 $ o $ $ _ {10-δ} $中的重金电子状态
Metal-to-metal transition and heavy-electron state in Nd$_4$Ni$_3$O$_{10-δ}$
论文作者
论文摘要
通过测量X射线衍射，电气电阻率，磁敏感性和热容量，研究了三层镍nd $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4 $ _4。晶体结构数据表明内部钙钛矿样层中的NI价较高。在环境压力下，电阻率在162 K处的跳跃，表明金属到金属过渡（MMT）。 MMT还具有磁化率下降，尖锐的特异性加热峰和各向同性的晶格收缩。低于$ \ sim $ 50 K，显示了$ t $依赖的电阻率上升，并带有负热膨胀。外部静水压力逐渐抑制电阻率逐渐跳跃，这与日志$ t $行为的减少相吻合。低温电子特异性热系数被提取为$ \ sim $ 150 mj k $^{ - 2} $ mol-fu $^{ - 1} $，相当于$ \ sim $ \ sim $ 50 mj k $^{ - 2} $ mol-ni $^{ - 1 $^{ - 1} $新颖的重型电子状态以及电阻率的对数温度依赖性通过Ni $^{3+} $中心的近相中效应来解释（ndnio $ _3 $）$ _ 3 $三层。
The trilayer nickelate Nd$_4$Ni$_3$O$_{10-δ}$ ($δ\approx$ 0.15) was investigated by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and heat capacity. The crystal structure data suggest a higher Ni valence in the inner perovskite-like layer. At ambient pressure the resistivity shows a jump at 162 K, indicating a metal-to-metal transition (MMT). The MMT is also characterized by a magnetic susceptibility drop, a sharp specific-heat peak, and an isotropic lattice contraction. Below $\sim$ 50 K, a resistivity upturn with a log$T$ dependence shows up, accompanying with a negative thermal expansion. External hydrostatic pressure suppresses the resistivity jump progressively, coincident with the diminution of the log$T$ behavior. The low-temperature electronic specific-heat coefficient is extracted to be $\sim$ 150 mJ K$^{-2}$ mol-fu$^{-1}$, equivalent to $\sim$ 50 mJ K$^{-2}$ mol-Ni$^{-1}$, indicating an unusual heavy-electron correlated state. The novel heavy-electron state as well as the logarithmic temperature dependence of resistivity is explained in terms of the Ni$^{3+}$ centered Kondo effect in the inner layer of the (NdNiO$_3$)$_3$ trilayers.
