- #1
broegger
- 257
- 0
Hi,
In the solid form FeO, CoO and NiO all has the NaCl-structure (simple cubic). In a series of diffraction experiments with x-rays ([tex]\lambda = 0.15406~\text{nm}[/tex]) one found reflexes from the (111), (200) and (220)-planes with the following [tex]\theta[/tex]-values ([tex]\theta[/tex] is the angle in Bragg's law, [tex]2d\sin\theta=\lambda[/tex]):
FeO: 18.04 20.95 30.28
CoO: 18.26 21.20 30.77
NiO: 18.63 21.64 31.45
The first number is the angle corresponding to the reflection from the (111)-plane, the second number corresponds to reflection from the (200)-plane and the third from the (220)-plane.
Question: What are the axis length for the three unit cells? Any hints?
In the solid form FeO, CoO and NiO all has the NaCl-structure (simple cubic). In a series of diffraction experiments with x-rays ([tex]\lambda = 0.15406~\text{nm}[/tex]) one found reflexes from the (111), (200) and (220)-planes with the following [tex]\theta[/tex]-values ([tex]\theta[/tex] is the angle in Bragg's law, [tex]2d\sin\theta=\lambda[/tex]):
FeO: 18.04 20.95 30.28
CoO: 18.26 21.20 30.77
NiO: 18.63 21.64 31.45
The first number is the angle corresponding to the reflection from the (111)-plane, the second number corresponds to reflection from the (200)-plane and the third from the (220)-plane.
Question: What are the axis length for the three unit cells? Any hints?