键合所决定的热学性质 100 50 0 -50 Empirical Lennard-Jones o特时时 -100 3.0 4.0 5.0 6.0 7.0 8.0 R(A)
键合所决定的热学性质
键合所决定的热学性质 热容与熔点Heat capacity and melting point *胡克定律looke'slaw:F=o,k个mf↑ 女陶瓷Ceramics:键合强而原子轻strong bonds and light atoms..对于小 的位移For small x,频率高f is big.高的热容和熔点high Cp and Tm 2 热膨胀Thermal expansion 势阱深而窄Deep and narrow well in ceramics:small expansion 3 热传导Heat conduction 弹簧网络Spring network 声子Phonon:以声速传播的波wave travel at the speed of sound.是粒子 振动的结果，T↑(<400℃)，f↑A↑ 声子散射Phonon scatter:多孔porous,.非晶amorphous↑，简单晶体 simple 光子Photon:在透明和多孔材料中尤其重要Especially important in transparent and porous materials 电子Electron
键合所决定的热学性质 1. 热容与熔点Heat capacity and melting point 胡克定律Hooke's law: F=kx, k↑ m ↓f ↑ 陶瓷Ceramics : 键合强而原子轻strong bonds and light atoms. 对于小 的位移For small x, 频率高f is big. 高的热容和熔点high Cp and Tm. 2. 热膨胀Thermal expansion 势阱深而窄Deep and narrow well in ceramics: small expansion 3. 热传导Heat conduction 弹簧网络Spring network 声子Phonon: 以声速传播的波wave travel at the speed of sound. 是粒子 振动的结果, T ↑(<400 ℃), f ↑ A↑ 声子散射Phonon scatter: 多孔porous, 非晶amorphous ↑, 简单晶体 simple ↓ 光子Photon: 在透明和多孔材料中尤其重要 Especially important in transparent and porous materials 电子Electron
应用的例子 外表面Exterior:高纯非晶石英纤维high purity amorphous silica fibers. ◆最高温区：高辐射度玻璃的增加层，可短时承受高达1480℃的高温。 955° 315° 650° Temperatures are in maximum 1465。 Celsius degrees. Temps marked with 1480 exposure an signify ascent te m pe rature tem peratures. Temp *1175° (°C) 425° 980° 660 T (Aluminum) mp *430° *405° *420° 175 0.0 3.5 Tile Thickness (in)
应用的例子 外表面Exterior: 高纯非晶石英纤维high purity amorphous silica fibers. 最高温区: 高辐射度玻璃的增加层，可短时承受高达1480 ℃ 的高温。 955 1175 430 405 425 420 980 1465 650 315 Temperatures are in Celsius degrees. Temps marked with an * signify ascent temperatures. * * * * * maximum exposure temperature 1480 Temp ( C) 660 175 0.0 Tile Thickness 3.5 T (Aluminum) m p (in)
电学行为 insulators sem iconductors metals 1020 106 10~2 108 -4 100 108 puotrerp sseta unluewIe8 Conductivity (ohm -1cm-1
电学行为
电学行为 Energy band Energy band gap Energy band Interatomic Equilibrium separation interatomic spacing 能带Energy band,带隙band gap 价带Valence band, w 导带conduction band w Metals Semiconductors E Insulators
电学行为 能带Energy band, 带隙band gap 价带Valence band, 导带conduction band E Metals Semiconductors Insulators