EXAMPLE PROBLEM 5.1 Calculate the equilibrium number of vacancies per cubic meter for copper at1000 C. The energy for vacancy formation is 0.9 e V/atom the atomic weight and density (at 1000C)for copper are 63.5 g/mol and 8.40 g/cm, respectively SOLUTION This problem may be solved by using Equation 5. 1; it is first necessary, however, to determine the value of N, the number of atomic sites per cubic meter for copper, from its atomic weight A Cu, its density, and Avogadros number NA, according to
EXAMPLE PROBLEM 5.1 Calculate the equilibrium number of vacancies per cubic meter for copper at1000 ℃. The energy for vacancy formation is 0.9 eV/atom; the atomic weight and density (at 1000℃) for copper are 63.5 g/mol and 8.40 g/cm3 , respectively. SOLUTION This problem may be solved by using Equation 5.1; it is first necessary, however,to determine the value of N, the number of atomic sites per cubic meter for copper, from its atomic weight ACu , its density , and Avogadro’s number NA, according to
N I Cu (6.023×1023 atoms/mo(8.40g/cm3)(10°cm3m2 63. 5 g/mol =8:0×1028 atoms/n Thus, the number of vacancies at 1000'C(1273 K) is equal to Nr=Nexp( kT (8.0 X 1028 atoms/m)exp 0.9eV) (8.62×10-eV/K)(1273K =2. x 1025 vacancies/m
●)●)● def igure 5.3 Fis
Figure 5.3
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2. 线缺陷(位错Dislocation)： 仅一维尺寸可与晶体线度比拟的缺陷 一或数列原子发生有规则的错排 EF ⊥ BB’ 1） 棱位错(刃位错 Edge Dislocation) 位错线与滑移方向(柏格斯矢量)垂直 压力、拉力