[A]No doubt, it has the prefix “ferro”- meaning iron but the fact is that MOST FERROELECTRIC MATERIALS DO NOT CONTAIN IRON.

[B] Ferroelectricity is a property of certain materials that have a spontaneous electric polarization which can be reversed by the application of an external electric field.Croconic acid is an excellent organic ferroelectric and its spontaneous polarization is close to that of barium titanate; one of the representative ferroelectric ceramics.

[C]Again, there may be a misconception that the ferroelectric mateials need to be paramagnetic/ ferromagnetic. On the contrary, there need not be present any any unpaired electrons. More so, there should not be any electron in “d” subshell.

[D]It is reasoned out as follows:

(i)Typically, materials demonstrate ferroelectricity only below a certain phase transition temperature, called the Curie temperature, Tc, and are paraelectric above this temperature.

(ii) The results show that the electronic polarization is 20 times the ionic polarization.

(iii)The two(electronic polarization and ionic polarization ) point in opposite directions.

So:

(a) it will be better if they do not have unpaired electrons at all because the electronic and ionic polarization oppose each other to decrease the net polarizability and the ferroelectricity may desrease or may even vanish.

(b)If at all the unpaired electrons are a must,they should not be present in “d” subshell because their polarization effect is more than “s” or “f”’ electrons.

There are several books which explains ferroelectricity in great details. Very quickly you can go through these slides...might be helpful for you:

https://www.staff.ncl.ac.uk/j.p.goss/MMG/PowerPoint/Ferroelectrics.ppt

[A]No doubt, it has the prefix “ferro”- meaning iron but the fact is that MOST FERROELECTRIC MATERIALS DO NOT CONTAIN IRON.

[B] Ferroelectricity is a property of certain materials that have a spontaneous electric polarization which can be reversed by the application of an external electric field.Croconic acid is an excellent organic ferroelectric and its spontaneous polarization is close to that of barium titanate; one of the representative ferroelectric ceramics.

[C]Again, there may be a misconception that the ferroelectric mateials need to be paramagnetic/ ferromagnetic. On the contrary, there need not be present any any unpaired electrons. More so, there should not be any electron in “d” subshell.

[D]It is reasoned out as follows:

(i)Typically, materials demonstrate ferroelectricity only below a certain phase transition temperature, called the Curie temperature, Tc, and are paraelectric above this temperature.

(ii) The results show that the electronic polarization is 20 times the ionic polarization.

(iii)The two(electronic polarization and ionic polarization ) point in opposite directions.

So:

(a) it will be better if they do not have unpaired electrons at all because the electronic and ionic polarization oppose each other to decrease the net polarizability and the ferroelectricity may desrease or may even vanish.

(b)If at all the unpaired electrons are a must,they should not be present in “d” subshell because their polarization effect is more than “s” or “f”’ electrons.

Ferroelectricity is a broken symmetry phase where in electric dipoles orient themselves in an ordered fashion. A ferroelectric crystal is spontaneously polarized below certain temperature called Curie Temperature. As the temperature  is reduced some optical phonon modes   become unstable and a so to say  "a frozen displacement state" results. A complete phonon dispersion curve is necessary to understand ferroelectricity  in a material.

Ferroelectricity is related to an intrinsic dipole generated by the structure of the material. To be ferroelectric this dipole must have the ability to be switched in sign following an external electric field.

Is a property of crystalline materials that  as a necessary condition do not present center of symmetry.

The intrisic electric dipole can lie along a crystallografic direction or in a crystallographic plane.   

 The microscopic theory (physical)  about the development of ferroelectricity is quite complex and is related to the so colled "soft mode" behaviour coming from the non-polar state. 

After Curie temperatura, what happens depends on the crystal structure of the high temperature phase and the  type of  the phase transition. Usually what happens is the appearance  of symmetry centre that  prevents ferroelectricity.  The high temperatura phase is usually paraelectric. .  

The microscopic origin of magnetism in all magnets is basically the same which is the presence of partially filled d or f shells in transition metals or rare earth ions. These ions possess localized spin or magnetic moment and exchange interactions between the localized moments lead to magnetic order.

In ferroelectrics, the situation is quite different as there are several different microscopic sources of ferroelectricity.

1) Ferroelectrics due to lone pairs

2) Ferroelectricity due to charge ordering

3) “Geometric” ferroelectricity

4) Magnetically driven ferroelectricity

The detail can be found in any ferroelectric text book.