当前位置：
X-MOL 学术
›
Cryst. Growth Des.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
One-Order Decrease of Thermal Conductivity in Nanostructured ZrTe5 and HfTe5 Crystals
Crystal Growth & Design ( IF 3.2 ) Pub Date : 2019-12-26 , DOI: 10.1021/acs.cgd.9b01108 Yan-Yan Zhang , Chen Di , Yang-Yang Lv , Song-Tao Dong 1 , Jian Zhou , Shu-Hua Yao , Y. B. Chen , Ming-Hui Lu , Yan-Feng Chen
Crystal Growth & Design ( IF 3.2 ) Pub Date : 2019-12-26 , DOI: 10.1021/acs.cgd.9b01108 Yan-Yan Zhang , Chen Di , Yang-Yang Lv , Song-Tao Dong 1 , Jian Zhou , Shu-Hua Yao , Y. B. Chen , Ming-Hui Lu , Yan-Feng Chen
Affiliation
|
Thermoelectric materials have been hotly explored for potential applications of environmentally friendly electrical generators and freon-free refrigerators. ZrTe5 and HfTe5 crystals have a superior power factor but relative large thermal conductivity. To decrease their thermal conductivity, we here grew ZrTe5 and HfTe5 with nanostructures by optimizing the growth parameters, with a growth mechanism that follows nucleation-then-nuclei-coalescence. Microstructure characterizations verify that nanostructured ZrTe5 and HfTe5 crystals have not only a layered microstructure but also nanostripe morphology. For comparison, we had grown compact ZrTe5 crystals by the flux method that mainly have a layered microstructure. Remarkably, the maximum thermal conductivity of nanostructured ZrTe5 and HfTe5 crystals can be suppressed to as small as 0.45 W m–1 K–1, one order lower than the theoretical value and three times smaller than that of compact ZrTe5 and HfTe5. Theoretical cumulative thermal conductivities, to simulate the effect of boundary scattering in nanostructured ZrTe5, roughly agree with experimental results. Phenomenological thermal conductivity analysis verifies that the phonon mean-free paths of nanostructured ZrTe5 and HfTe5 reach the thickness of a monolayer (Ioffe–Regel criterion of phonon transport). Raman spectroscopy substantiates that the quasi-particle lifetime of optical phonons in nanostructured ZrTe5 and HfTe5 crystals is nearly four times larger than the phonon transport lifetime, which proves the pronounced effect of the microstructure on thermal conductivity from a spectroscopic viewpoint. Our work may provide an efficient method to modulate thermal conductivity by microstructure engineering through modified crystal growth.
中文翻译：
纳米结构ZrTe 5和HfTe 5晶体的导热系数一阶下降
对于环境友好型发电机和无氟利昂冰箱的潜在应用，热电材料已经进行了热烈的探索。ZrTe 5和HfTe 5晶体具有较高的功率因数，但具有相对较大的热导率。为了降低它们的热导率，我们在这里通过优化生长参数来生长具有纳米结构的ZrTe 5和HfTe 5，其生长机制遵循成核-随后-核结合。微观结构表征证明，纳米结构的ZrTe 5和HfTe 5晶体不仅具有层状的微观结构，而且具有纳米条的形态。为了进行比较，我们已经种植了紧凑的ZrTe 5通量法测定的晶体主要具有分层的微结构。值得注意的是，纳米结构ZrTe 5和HfTe 5晶体的最大热导率可以抑制到0.45 W m –1 K –1，比理论值低一个数量级，比紧凑ZrTe 5和HfTe 5的三倍小。。理论上的累积热导率，用于模拟纳米结构ZrTe 5中边界散射的影响，与实验结果基本吻合。现象学热导率分析验证了纳米结构ZrTe 5和HfTe 5的声子无均值路径达到单层的厚度（声子传输的Ioffe-Regel准则）。拉曼光谱证实了纳米ZrTe 5和HfTe 5晶体中光学声子的准粒子寿命几乎是声子传输寿命的四倍，这从光谱角度证明了微结构对热导率的显着影响。我们的工作可能会提供一种有效的方法，通过微结构工程通过改进的晶体生长来调节热导率。
更新日期：2019-12-27
中文翻译：
纳米结构ZrTe 5和HfTe 5晶体的导热系数一阶下降
对于环境友好型发电机和无氟利昂冰箱的潜在应用，热电材料已经进行了热烈的探索。ZrTe 5和HfTe 5晶体具有较高的功率因数，但具有相对较大的热导率。为了降低它们的热导率，我们在这里通过优化生长参数来生长具有纳米结构的ZrTe 5和HfTe 5，其生长机制遵循成核-随后-核结合。微观结构表征证明，纳米结构的ZrTe 5和HfTe 5晶体不仅具有层状的微观结构，而且具有纳米条的形态。为了进行比较，我们已经种植了紧凑的ZrTe 5通量法测定的晶体主要具有分层的微结构。值得注意的是，纳米结构ZrTe 5和HfTe 5晶体的最大热导率可以抑制到0.45 W m –1 K –1，比理论值低一个数量级，比紧凑ZrTe 5和HfTe 5的三倍小。。理论上的累积热导率，用于模拟纳米结构ZrTe 5中边界散射的影响，与实验结果基本吻合。现象学热导率分析验证了纳米结构ZrTe 5和HfTe 5的声子无均值路径达到单层的厚度（声子传输的Ioffe-Regel准则）。拉曼光谱证实了纳米ZrTe 5和HfTe 5晶体中光学声子的准粒子寿命几乎是声子传输寿命的四倍，这从光谱角度证明了微结构对热导率的显着影响。我们的工作可能会提供一种有效的方法，通过微结构工程通过改进的晶体生长来调节热导率。
京公网安备 11010802027423号