论文标题
发现NB $ _4 $ sisb $ _2 $的超导性的发现，v $ _4 $ _4 $ sisb $ _2 $ type结构和间隙掺杂的含义在其物理属性上
Discovery of Superconductivity in Nb$_4$SiSb$_2$ with a V$_4$SiSb$_2$-Type Structure and Implications of Interstitial Doping on its Physical Properties
论文作者
论文摘要
我们报告了发现，结构分析和NB $ _4 $ _4 $ sisb $ _2 $的物理特性 - 迄今未知的化合物在V $ _4 $ _4 $ _4 $ sisb $ _2 $ _2 $ -Type结构中，带有Tetragonal Space Group $ i4/MCM $/MCM $和单位电池参数$ a $ a $ a $ = 10.3638（2） $ \ MATHRING {\ MATHRM {A}} $和$ C $ = 4.9151（2）$ \ MATHRING {\ MATHRM {a}} $。我们发现NB $ _4 $ sisb $ _2 $是在过渡到超导状态下在$ t _ {\ rm c} \ $ 1.6 k下过渡到超导状态的金属。超导性的大量性质是通过在特定的不良热量中观察到$ n formantive n formantion n formantine n formantion n pressive fee the formantion n pressive fee tht n formantion n formantion n formantive fee tht Pranistion n formantive fee for Angorminition ndumintion的特定性热量。 c}）/γt_ {\ rm c} = 1.33 \，{\ rm mj} \，{\ rm mol}^{ - 1} \，{\ rm k}^{ - 2} $。我们发现，对于NB $ _4 $ SISB $ _2 $，$ 4B $ WYCKOFF位置上的无人居住的站点可以部分用CU，PD或PT占据。低温电阻率测量表明，所有三种化合物的过渡率在$ t _ {\ rm c} \ oft \，1.2 \，1.2 \，{\ rm k} $ for nb $ _4 $ _4 $ _4 $ cu $ _ {0.2} $ _ {0.2} {\ rm k} $ for nb $ _4 $ pd $ _ {0.2} $ sisb $ _2 $以及nb $ _4 $ pt $ _ {0.14} $ sisb $ _2 $。与母体化合物相比，从此以后，将电子原子添加到这些空隙位置中，从而降低了超导过渡温度。
We report on the discovery, structural analysis, and the physical properties of Nb$_4$SiSb$_2$ -- a hitherto unknown compound crystallizing in the V$_4$SiSb$_2$-type structure with the tetragonal space group $I4/mcm$ and unit cell parameters $a$ = 10.3638(2) $\mathring{\mathrm{A}}$ and $c$ = 4.9151(2) $\mathring{\mathrm{A}}$. We find Nb$_4$SiSb$_2$ to be a metal undergoing a transition to a superconducting state at a critical temperature of $T_{\rm c} \approx$ 1.6 K. The bulk nature of the superconductivity in this material is confirmed by the observation of a well defined discontinuity in specific heat with a normalized specific heat jump of $ΔC(T_{\rm c})/γT_{\rm c} = 1.33\, {\rm mJ}\, {\rm mol}^{-1}\, {\rm K}^{-2}$. We find that for Nb$_4$SiSb$_2$, the unoccupied sites on the $4b$ Wyckoff position can be partially occupied with Cu, Pd, or Pt. Low-temperature resistivity measurements show transitions to superconductivity for all three compounds at $T_{\rm c} \approx\, 1.2\, {\rm K}$ for Nb$_4$Cu$_{0.2}$SiSb$_2$, and $T_{\rm c} \approx\, 0.8\, {\rm K}$ for Nb$_4$Pd$_{0.2}$SiSb$_2$ as well as for Nb$_4$Pt$_{0.14}$SiSb$_2$. The addition of electron-donor atoms into these void positions, henceforth, lowers the superconducting transition temperature in comparison to the parent compound.
