Thank you so much Hisay Lama

https://www.amazon.com/Principles-Electronic-Materials-Devices-Kasap/dp/0073104647

You can look into chapter 7 Dielectric properties and materials chapter for details and insights. There are several kind of polarization, you have to find out what kind of polarization works in your materials by changing the frequency. As suggested before, you have to conduct experiment for determining but first have a read on that chapter. This will provide the insights while understanding the results of your experiment. 

I think, this will help you :) All the best for your research :) 

I know that some time ago PhD thesis of Nicolas Pannacci in University of Nice was performed (http://www.theses.fr/2006NICE4097). It was dedicated directly to the question you are asking. I think that you can find his other publications.

Good luck

Thank you so much I appreciate that