晶体缺陷作业

晶体缺陷作业
-标准化文件发布号：（9456-EUATWK-MWUB-WUNN-INNUL-DDQTY-KII
1 什么叫肖特基缺陷和弗兰克耳缺陷？用Kroger-Vink 记号分别描述AgBr 中的弗兰克耳缺陷和MgO 中的肖特基缺陷形成的缺陷化学方程，写出ZnO 中掺杂Al 2O 3空位补偿和电子补偿的缺陷化学方程。

2 If cupric oxide (CuO) is exposed to reducing atmospheres at elevated
temperatures, some of the Cu 2+ ions will become Cu +.
(a) Under these conditions, name one crystalline defect that you would expect to form in order to maintain charge neutrality.
(b) How many Cu + ions are required for the creation of each defect?
(c) How would you express the chemical formula for this nonstoichiometric material?
3 (a) Suppose that Li 2O is added as an impurity to CaO. If the Li + substitutes for Ca 2+, what kind of vacancies would you expect to form
How many of these vacancies are created for every Li added?
(b) Suppose that CaCl 2 is added as an impurity to CaO. If the Cl - substitutes for O 2-, what kind of vacancies would you expect to form
How many of the vacancies are created for every Cl - added?
4 纯铁的空位形成能为1.5X10-19J/atom ，将纯铁加热至850℃后激冷至室温20℃,若高温下的空位全部保留，试求过饱和空位浓度与室温平衡空位浓度的比值。

5 已知铜的晶体结构为fcc,点阵常数a=0.225nm ，切变模量210104-⋅⨯=m N G ，试分别计算柏氏矢量为]121[6
]111[2]111[3]110[2a a a a
的位错应变能。

6在图示的Cu晶界上有一双球冠形第二相，已知Cu的大角度晶界能为2
J•，
5.0m
(1)分别计算当o
o90
θ时Cu与第二相之间的相界面能；
=θ
,
60=
(2)讨论它们若处在三个Cu晶粒的交线上将是什么形状。

7 计算并比较体心立方晶体中（100），（110），（111）面的比表面能。

设每对原子键能为ε，点阵常数为a。