The spontaneous polarization of ferroelectric materials implies a hysteresis effect which can be used as a memory function.
Today the term multiferroic has been expanded to include materials which exhibit any type of long range magnetic ordering, spontaneous electric polarization, and/or ferroelasticity.
A necessary but not sufficient condition for the appearance of spontaneous electric polarization is the absence of inversion symmetry.
The total average spontaneous polarization is decreased due to the spread of the oscillation angles.
The change in the spontaneous polarization results in a change in the surface charge.
A change in the spontaneous polarization of a material in response to a change in temperature is called pyroelectricity.
This free energy has the shape of a double well potential with two free energy minima at , where P is the spontaneous polarization.
If , using the same approach as above, the spontaneous polarization may be obtained as:
Wurtzite phases allow spontaneous polarization in the (0001) direction.
Flexoelectricity is a property of a dielectric material whereby it exhibits a spontaneous electrical polarization induced by a strain gradient.