Measuring the temperature dependence of material properties is a standard method for better understanding the microscopic origins for that property. Surprisingly, only a few experimental studies of thermal boundary conductance at high temperatures exist. This lack of high temperature data makes it difficult to evaluate competing theories for how inelastic processes contribute to thermal conductance. To address this, we report time domain thermoreflectance measurements of the thermal boundary conductance for TiN on diamond, silicon-carbide, silicon, and germanium between 120 and 1000 K. In all systems, the interface conductance increases monotonically without stagnating at higher temperatures. For TiN/SiC interfaces, G ranges from 330 to 1000 MW/m2-K, with a room temperature conductance of 750 MW/m2-K. The interface conductance for TiN/diamond ranges from 140 to 950 MW/m2-K. Notably, for all four interfacial systems, the conductance continues to increase with temperature even after all phonon modes in the vibrationally soft material are thermally excited. This observation suggests that inelastic processes are significant contributors to the thermal conductance in all four interfacial systems, regardless of whether the materials forming the interface are vibrationally similar or dissimilar. Our study fills a notable gap in the literature for how interfacial conductance evolves at high temperatures and tests burgeoning theories for the role of inelastic processes in interfacial thermal transport.

中文翻译：

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高温下氮化钛与IV族半导体界面的热导率


测量材料特性的温度依赖性是更好地了解该特性的微观起源的标准方法。令人惊讶的是，只有少数关于高温下热边界电导的实验研究。由于缺乏高温数据，很难评估非弹性过程如何影响热导的竞争理论。为了解决这个问题，我们报告了 120 至 1000 K 范围内金刚石、碳化硅、硅和锗上 TiN 热边界电导的时域热反射测量。在所有系统中，界面电导单调增加，在较高温度下不会停滞。对于 TiN/SiC 界面，G 范围为 330 至 1000 MW/m2-K，室温电导为 750 MW/m2-K。 TiN/金刚石的界面电导范围为 140 至 950 MW/m2-K。值得注意的是，对于所有四种界面系统，即使在振动软材料中的所有声子模式都被热激发之后，电导仍然随着温度而继续增加。这一观察结果表明，无论形成界面的材料在振动上是否相似或不同，非弹性过程都是所有四个界面系统中热导的重要贡献者。我们的研究填补了文献中关于界面电导在高温下如何演变的一个显着空白，并测试了非弹性过程在界面热传输中的作用的新兴理论。