| 5 | 1/1 | 返回列表 |
| 查看: 2135 | 回復(fù): 6 | ||||
| 當(dāng)前只顯示滿足指定條件的回帖,點(diǎn)擊這里查看本話題的所有回帖 | ||||
[交流]
【求助】castep中光學(xué)性能吸收反射譜的單位是什么?
|
||||
|
請問,castep中計算光學(xué)性能的吸收譜中,單位是什么? 他的幫助里沒找到相關(guān)的說明,另外,這個吸收系數(shù)為什么這么高?我算的碳管吸收有的峰值30000這么多。請高人給俺解惑一下。 反射系數(shù)的話就是簡單的強(qiáng)度反射率了吧,可以認(rèn)為是沒有單位么?這個參量中峰值最大的才0.04. 不知道這么理解對否。 這里現(xiàn)行謝過。 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:
+2/90
+1/84
+1/84
+1/81
+1/60
+1/28
+2/28
+1/20
+1/17
+2/16
+1/13
+1/11
+1/9
+1/5
+1/5
+1/4
+1/3
+1/3
+1/3
+1/3
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 一志愿北京化工大學(xué)070300 學(xué)碩336求調(diào)劑 +3 | vv迷 2026-03-21 | 4/200 |
|
|---|---|---|---|---|
|
[考研] 考研調(diào)劑 +3 | 呼呼?~+123456 2026-03-21 | 3/150 |
|
|
[考研] 0703化學(xué)調(diào)劑 +11 | 妮妮ninicgb 2026-03-15 | 15/750 |
|
|
[基金申請] 山東省面上項目限額評審 +3 | 石瑞0426 2026-03-19 | 3/150 |
|
|
[考研] 311求調(diào)劑 +3 | 勇敢的小吳 2026-03-20 | 3/150 |
|
|
[考研] 296求調(diào)劑 +4 | www_q 2026-03-20 | 4/200 |
|
|
[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] 0805材料320求調(diào)劑 +3 | 深海物語 2026-03-20 | 3/150 |
|
|
[考研] 323求調(diào)劑 +3 | 洼小桶 2026-03-18 | 3/150 |
|
|
[考研] 一志愿 西北大學(xué) ,070300化學(xué)學(xué)碩,總分287,雙非一本,求調(diào)劑。 +4 | 晨昏線與星海 2026-03-19 | 4/200 |
|
|
[考研] 350求調(diào)劑 +5 | weudhdk 2026-03-19 | 5/250 |
|
|
[考研] 260求調(diào)劑 +3 | 朱芷琳 2026-03-20 | 3/150 |
|
|
[考研] 一志愿吉林大學(xué)材料學(xué)碩321求調(diào)劑 +11 | Ymlll 2026-03-18 | 15/750 |
|
|
[考研] 求調(diào)劑 +3 | eation27 2026-03-20 | 3/150 |
|
|
[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 2026-03-20 | 3/150 |
|
|
[考研] 298-一志愿中國農(nóng)業(yè)大學(xué)-求調(diào)劑 +9 | 手機(jī)用戶 2026-03-17 | 9/450 |
|
|
[考研] 085600材料與化工調(diào)劑 324分 +10 | llllkkkhh 2026-03-18 | 12/600 |
|
|
[考研] 328求調(diào)劑,英語六級551,有科研經(jīng)歷 +4 | 生物工程調(diào)劑 2026-03-16 | 12/600 |
|
|
[考研] 生物學(xué)071000 329分求調(diào)劑 +3 | 我愛生物生物愛?/a> 2026-03-17 | 3/150 |
|
|
[考研] 070300化學(xué)學(xué)碩求調(diào)劑 +6 | 太想進(jìn)步了0608 2026-03-16 | 6/300 |
|