| 5 | 1/1 | 返回列表 |
| 查看: 2136 | 回復(fù): 6 | ||||
| 當(dāng)前只顯示滿(mǎn)足指定條件的回帖,點(diǎn)擊這里查看本話(huà)題的所有回帖 | ||||
redskywei木蟲(chóng) (著名寫(xiě)手)
|
[交流]
【求助】castep中光學(xué)性能吸收反射譜的單位是什么?
|
|||
|
請(qǐng)問(wèn),castep中計(jì)算光學(xué)性能的吸收譜中,單位是什么? 他的幫助里沒(méi)找到相關(guān)的說(shuō)明,另外,這個(gè)吸收系數(shù)為什么這么高?我算的碳管吸收有的峰值30000這么多。請(qǐng)高人給俺解惑一下。 反射系數(shù)的話(huà)就是簡(jiǎn)單的強(qiáng)度反射率了吧,可以認(rèn)為是沒(méi)有單位么?這個(gè)參量中峰值最大的才0.04. 不知道這么理解對(duì)否。 這里現(xiàn)行謝過(guò)。 我在幫助里仔細(xì)又找了一下,找到了相關(guān)公式,可是里面的量的說(shuō)明還是不能讓我得出吸收系數(shù)的單位是啥。我在5.0的Optical properties->Definition of optical constants下看到了公式,內(nèi)容如下(公式不知道怎么能搞上了,呵呵):CASTEP can calculate the optical properties of solids that are due to electronic transitions. In general, the difference in the propagation of an electromagnetic wave through vacuum and some other material can be described by a complex refractive index, N: Eq. CASTEP 48 In vacuum N is real, and equal to unity. For transparent materials it is purely real, the imaginary part being related to the absorption coefficient by: Eq. CASTEP 49 The absorption coefficient indicates the fraction of energy lost by the wave when it passes through the material, so that the intensity at the distance x from the surface is I(x)=I(0)exp(-2πηx), where I(0) is the intensity of the incident light. The reflection coefficient can be obtained for the simple case of normal incidence onto a plane surface by matching both the electric and magnetic fields at the surface: Eq. CASTEP 50 However, when performing calculations of optical properties it is common to evaluate the complex dielectric constant and then express other properties in terms of it. The complex dielectric constant, ε(ω), is given by: Eq. CASTEP 51 and hence the relation between the real and imaginary parts of the refractive index and dielectric constant is: Eq. CASTEP 52 Another frequently used quantity for expressing optical properties is the optical conductivity, σ(ω): Eq. CASTEP 53 Optical conductivity is usually used to characterize metals, however CASTEP is aimed more toward the optical properties of insulators and semiconductors. The main difference between the two is that intraband transitions play important role in the IR part of the optical spectra of metals and these transitions are not considered at all in CASTEP. A further property that can be calculated from the complex dielectric constant is the energy loss function. It describes the energy lost by an electron passing through a homogeneous dielectric material and is given by: Eq. CASTEP 54 還請(qǐng)高人不吝賜教~~~ [ Last edited by redskywei on 2010-11-29 at 20:28 ] |
各種各樣 |
» 搶金幣啦!回帖就可以得到:
+5/180
+2/150
+1/81
+1/72
+2/64
+1/51
+1/30
+1/16
+1/15
+1/12
+1/10
+1/10
+1/8
+1/8
+1/7
+1/3
+1/2
+1/1
+1/1
+1/1
木蟲(chóng) (正式寫(xiě)手)
至尊木蟲(chóng) (小有名氣)
鐵桿木蟲(chóng) (著名寫(xiě)手)
木蟲(chóng) (正式寫(xiě)手)
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 一志愿武理材料工程348求調(diào)劑 +3 |  ̄^ ̄゜汗 2026-03-19 | 5/250 |
|
|---|---|---|---|---|
|
[考研] 求調(diào)劑 +7 | Auroracx 2026-03-22 | 7/350 |
|
|
[考研] 285求調(diào)劑 +6 | ytter 2026-03-22 | 6/300 |
|
|
[考研] 286分人工智能專(zhuān)業(yè)請(qǐng)求調(diào)劑愿意跨考! +4 | lemonzzn 2026-03-17 | 8/400 |
|
|
[考研] 廣西大學(xué)材料導(dǎo)師推薦 +3 | 夏夏夏小正 2026-03-17 | 5/250 |
|
|
[考研] 化學(xué)工程321分求調(diào)劑 +18 | 大米飯! 2026-03-15 | 22/1100 |
|
|
[考研] 0805 316求調(diào)劑 +3 | 大雪深藏 2026-03-18 | 3/150 |
|
|
[考研] 工科0856求調(diào)劑 +3 | 沐析汀汀 2026-03-21 | 3/150 |
|
|
[考研] 302求調(diào)劑 +12 | 呼呼呼。。。。 2026-03-17 | 12/600 |
|
|
[考研] 277材料科學(xué)與工程080500求調(diào)劑 +6 | 自由煎餅果子 2026-03-16 | 6/300 |
|
|
[考研] 306求調(diào)劑 +4 | chuanzhu川燭 2026-03-18 | 4/200 |
|
|
[考研] 材料工程(專(zhuān))一志愿985 初試335求調(diào)劑 +3 | hiloiy 2026-03-17 | 4/200 |
|
|
[考研] 294求調(diào)劑材料與化工專(zhuān)碩 +15 | 陌の森林 2026-03-18 | 15/750 |
|
|
[考研] 中南大學(xué)化學(xué)學(xué)碩337求調(diào)劑 +3 | niko- 2026-03-19 | 6/300 |
|
|
[考研] 材料學(xué)碩297已過(guò)四六級(jí)求調(diào)劑推薦 +11 | adaie 2026-03-19 | 11/550 |
|
|
[考研] 0817 化學(xué)工程 299分求調(diào)劑 有科研經(jīng)歷 有二區(qū)文章 +22 | rare12345 2026-03-18 | 22/1100 |
|
|
[考研] 一志愿南理工085701環(huán)境302求調(diào)劑院校 +3 | 葵梓衛(wèi)隊(duì) 2026-03-20 | 3/150 |
|
|
[考研] 材料與化工求調(diào)劑 +7 | 為學(xué)666 2026-03-16 | 7/350 |
|
|
[考研] 328求調(diào)劑,英語(yǔ)六級(jí)551,有科研經(jīng)歷 +4 | 生物工程調(diào)劑 2026-03-16 | 12/600 |
|
|
[考研] 321求調(diào)劑 +5 | 大米飯! 2026-03-15 | 5/250 |
|