【摘要】 利用键弛豫理论与局域键平均近似方法对过渡金属MoSe₂和WSe₂的热学参数进行了定量分析,建立了热膨胀系数、晶格常数、热应变分别与温度的函数关系式,揭示了层状半导体材料热学参量的温度效应物理机制,并获得了块体MoSe₂和WSe₂的德拜温度分别为276,260K.实验结果表明,热膨胀系数与德拜比热成正比,与原子结合能成反比;温度高于材料的德拜温度的1/3时,晶格常数、热应变与温度呈线性关系.更多还原

【Abstract】 Based on bond order-length-strength theory and local bond average approach,the thermal parameters of the transition metals MoSe₂ and WSe₂ were quantitatively analyzed,and the functional relations of thermal expansion coefficient（TEC）,lattice constant,thermal strain and temperature were established.It reveals the physical mechanism of the temperature effect of the thermal parameters of the layered semiconductor material:TEC is directly proportional to the Debye temperature and specific heat capacity,and is inversely proportional to the atomic cohesive energy.The lattice constant,thermal strain and temperature are linear when the temperature is higher than one third of the material’s Debye temperature.Debye temperatures of MoSe₂ and WSe₂ were 276,260 K.更多还原