论文标题
金属过渡金属氮化物中的异常热传输源自较强的电子 - phonon相互作用
Anomalous thermal transport in metallic transition-metal nitrides originated from strong electron-phonon interactions
论文作者
论文摘要
金属过渡金属氮化物（TMN）是许多应用的有前途的导电陶瓷，其热传输在设备设计中非常重要。与普通金属和非金属TMN相比，它发现金属锡和HFN具有异常的热传输行为。它们具有极大的固有声子导热率，这主要是由于较大的声音声子频率间隙。当考虑了声子 - 异位和声子 - 电子散射时，声子导热率通过两个数量级降低，这也诱导了声子导电性的非平凡温度无关的行为。嵌套费米表面都存在于锡和HFN中，这会导致强烈的电子偶联强度，并严重损害了声子和电子的传输。声子组件的总导热率异常较大，为300 K时的HFN为29％。还提出了薄膜的结果，并且表明可以有效地限制了声子导热率。我们的发现提供了对金属TMN中热传输的深入了解，并扩大了金属中的热传导理论的范围。
Metallic transition-metal nitrides (TMNs) are promising conductive ceramics for many applications, whose thermal transport is of great importance in device design. It is found metallic TiN and HfN hold anomalous thermal transport behaviors compared to common metals and nonmetallic TMNs. They have extremely large intrinsic phonon thermal conductivity mainly due to the large acoustic-optic phonon frequency gaps. The phonon thermal conductivity is reduced by two orders of magnitude as the phonon-isotope and phonon-electron scatterings are considered, which also induce the nontrivial temperature-independent behavior of phonon thermal conductivity. Nesting Fermi surfaces exist in both TiN and HfN, which cause the strong electron-phonon coupling strengths and heavily harm the transport of phonons and electrons. The phonon component takes an abnormally large ratio in total thermal conductivity, as 29% for TiN and 26% for HfN at 300 K. The results for thin films are also presented and it is shown that the phonon thermal conductivity can be efficiently limited by size. Our findings provide a deep understanding on the thermal transport in metallic TMNs and expand the scope of heat conduction theory in metal.
