论文标题
固体氘甲烷的负热膨胀
Negative Thermal Expansion in Solid Deuteromethane
论文作者
论文摘要
计算仅旋转隧道模式至关重要的低温区域的固体CD $ _4 $ iii的恒定压力的热膨胀是必不可少的，并且可以忽略声子和库的效果。发现在MK区域存在负热膨胀的巨大峰。该峰值的高度是可比的，甚至超过了固体n $ _2 $，co，o $ _2 $或CH $ _4 $的热膨胀。结果表明，与轻甲烷的情况一样，压力的效果是非常不寻常的：正如热力学grüneisen参数的压力依赖性所证明的那样（绝对值为负和大），实心CD $ _4 $随着压力的上升而变得越来越量子。
The thermal expansion at constant pressure of solid CD$_4$ III is calculated for the low temperature region where only the rotational tunneling modes are essential and the effect of phonons and librons can be neglected. It is found that in mK region there is a giant peak of the negative thermal expansion. The height of this peak is comparable or even exceeds the thermal expansion of solid N$_2$, CO, O$_2$ or CH$_4$ in their triple points. It is shown that like in the case of light methane, the effect of pressure is quite unusual: as evidenced from the pressure dependence of the thermodynamic Grüneisen parameter (which is negative and large in the absolute value), solid CD$_4$ becomes increasingly quantum with rising pressure.
