A Question about microwave diffraction (Bragg scattering)

[Jopi]

Hi,

at my Uni we have a lab course where we first take some measurements and then write a report about the experiment. Our current experiment was about microwave diffraction. First, we measured the wave length of the microwaves, and then proceeded to measure the intensity of the scattered radiation as a function of the angle between the plane of reflection and the incident radiation.
We obtained a plot which shows clearly the maxima predicted by the Bragg law:

n $$\lambda$$ = 2 d sin $$\theta$$

The problem is that there are other maxima, which are not explained by the Bragg law. One of these maxima is actually higher than the one given by Bragg law. What causes these other maxima? Is it the reflection from other reflection planes? I've been trying to find about this on the internet, but so far I haven't found anything.

 

[Jhero]

Hello,

Thank you for sharing your experience with the microwave diffraction experiment. It sounds like you have obtained some interesting results. The Bragg law is typically used to explain the diffraction pattern observed in X-ray diffraction experiments, but it can also be applied to other types of electromagnetic radiation such as microwaves.

In your experiment, the other maxima that you observed could be due to diffraction from other reflection planes, as you mentioned. This is known as multiple diffraction and it occurs when the incident radiation interacts with more than one set of parallel planes in the crystal. This can result in additional peaks in the diffraction pattern that are not predicted by the Bragg law.

Another possible explanation for these additional maxima could be imperfections in the crystal structure. These imperfections can cause slight variations in the spacing between the crystal planes, leading to multiple diffraction patterns.

I would suggest conducting further research on multiple diffraction and crystal imperfections to better understand the results of your experiment. It may also be helpful to consult with your lab instructor or a more experienced researcher in this field.

Overall, your results show that there is still much to be learned and explored in the field of microwave diffraction. Keep up the good work and continue to ask questions and seek answers to further your understanding of this phenomenon.

Best of luck with your future experiments and reports.