论文标题
在暴民中，高临界场超导性通过NB替换在P6/mmm结构中稳定在环境压力下
High critical field superconductivity at ambient pressure in MoB$_2$ stabilized in the P6/mmm structure via Nb substitution
论文作者
论文摘要
最近发现，在高高的压力下，暴民$ _2 $在临界温度（$ t_c $）上表现出超导性，高达32 k。超导性在从环境压力r $ $ $ $ \ bar {3} $结构到mgb $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 p6/mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm的结构均得到压力很高。这表明，二迪伯利德中的$ t_c $值非常高，不仅限于MGB $ _2 $，因此，如果可以将它们胁迫到MGB $ _2 $结构中，则其他二吡啶可能会发生类似的高$ T_C $值。在本文中，我们表明密度功能理论计算表明，声子自由能在r $ \ bar {3} $ m上稳定P6/mmm结构，而NB $ _ {1-x} $ _x $ $ _x $ _x $ _x $ _b $ b $ _2 $系列。 X射线衍射证实了合成的NB取代的MOB $ _2 $采用MGB $ _2 $ Crystal结构。高磁场电阻率测量和特定的热量测量表明，nb $ _ {1-x} $ mo $ $ _x $ b $ _2 $以$ t_c $高达8 K的超导性表现出超导性，而接近6 t的关键领域。
Recently it was discovered that, under elevated pressures, MoB$_2$ exhibits superconductivity at a critical temperature, $T_c$, as high as 32 K. The superconductivity appears to develop following a pressure-induced structural transition from the ambient pressure R$\bar{3}$m structure to an MgB$_2$-like P6/mmm structure. This suggests that remarkably high $T_c$ values among diborides are not restricted to MgB$_2$ as previously appeared to be the case, and that similarly high $T_c$ values may occur in other diborides if they can be coerced into the MgB$_2$ structure. In this paper, we show that density functional theory calculations indicate that phonon free energy stabilizes the P6/mmm structure over the R$\bar{3}$m at high temperatures across the Nb$_{1-x}$Mo$_x$B$_2$ series. X-ray diffraction confirms that the synthesized Nb-substituted MoB$_2$ adopts the MgB$_2$ crystal structure. High magnetic field electrical resistivity measurements and specific heat measurements demonstrate that Nb$_{1-x}$Mo$_x$B$_2$ exhibits superconductivity with $T_c$ as high as 8 K and critical fields approaching 6 T.
