It is rather easy but most of the published articles are confusing to differentiate between beta and gamma but for alpha, there should not be a problem.

I would suggest you to read the following articles:

1.Ramsundaram, S.; Yoon, S.; Kim, K. J.; Park, C. J. Polym. Sci. B:

Polym. Phys. 2008, 46, 2173.

2.Ince-Gunduz, B. S.; Alpern, R.; Amare, D.; Crawford, J.; Dolan,

B.; Jones, S.; Kobylarz, R.; Reveley, M.; Cebe, P. Polymer 2010, 51, 1485.

3.http://www.sciencedirect.com/science/article/pii/S0167577X11014212

4.http://pubs.acs.org/doi/abs/10.1021/jp201335j?journalCode=jpcbfk

I would suggest u to go through this review article....it helped me a lot.

Thanks Mr. Dipankar and Nusrat

Alpha: peak at 766 cm-1, and beta: peak at 840 cm-1

Nirul: Very careful about 840 cm-1 band as it is also the signature of gamma phase. So in order to avoid wrong interpretation: Cross check 1275 cm-1 (beta) and 1232 cm-1 (gamma) bands as these are the non confusing bands)I would say. But unfortunately in literature you may find more than 70% only plotted FTIR from 400 to 950 cm-1 and said 840 cm-1 carefully said as beta and also state it has higher melting temperature. As it is wrongly identified as beta phase instead of gamma thus it shows higher melting. Note that beta,alpha and then gamma: Melting order.

I suggest you read this paper which will help a lot:

"Zaarour B, Zhu L, Huang C, et al. Enhanced piezoelectric properties of randomly

oriented and aligned electrospun PVDF fibers by regulating the surface morphology. J Appl Polym Sci 2019; 136: 47049–47056."

Best Regards.

In the case of FTIR spectra of PVDF polymer, the alpha and beta peaks can be considered at the wavenumber of 762 cm-1 and 840cm-1, respectively. However, as per the reported articles, the Gamma phase also can occur at the wavenumber of 840cm-1. most of the cases alpha and beta phase are considered at the above said wavenumbers. For a detailed understanding, you can read different published articles also.

thanking You!