# Electric potential energy

1. ### stefano colom

5
my professor has explained Electric potential energy Law U=∫D*E above all the space. he said you can not use for some kind of materials. l can 't remember if they are Ferroelectricity or piezoelectric materials. then can you say to me the reason too? thank you

3. ### Darwin123

741
There is a hysteresis effect in ferroelectric materials, too.

4. ### stefano colom

5
but why couldn't l use for the ferroelectricity materials

5. ### Meir Achuz

2,059
The derivation of the D.E form requires that the relation between D and E be linear.
It is not for ferroelectric materials.