Question

在20摄氏度时铜粉末的样品一级衍射角为47.75度,1000摄氏度时是46.60度,求铜的线胀系数.

Answer 1

2dsinθ=λ

d=λ/2sinθ

d1=λ/2sinθ1=λ/2sin47.75=1.2354λ

d2=λ/2sinθ2=λ/2sin46.60=1.2641λ

线性膨胀系数

α=[(d2-d1)/d1]/(T2-T1)

=[(1.2641λ-1.2354λ)/1.2354λ]/(1273K-293K)=23.7×10^-6/K