1920

Ferroelectricity

• A ferroelectric material
• is like a ferromagnetic material
• except that a ferromagnetic material
• has a magnetic polarization,
• whereas a ferroelectric material
• has a electric polarisation.
• Because ferroelectricity
• can be controlled by an external electric field,
• ferroelectric material make tunable capacitors.
• Because hysteresis occurs in ferroelectric materials,
• they make random access memory
• for computers and RFID cards.

What to name it

• Erwin Schrödinger thought it should exist
• and coined the term.
• Although his report didn’t use Schrödinger’s term,
• Joseph Valasek discovered it in Rochelle salt.
• Ferroelectricity is a odd term for the effect
• because the prefix ferro means iron
• and ferroelectric materials do not contain iron.

Related to

• Ferroelectric materials
• are pyroelectric;
• not all pyroelectric materials
• are ferroelectric.
• Pyroelectric materials
• are piezoelectric;
• not all piezoelectric materials
• are pyroelectric.
• If it’s not piezoelectric,
• then it’s not pyroelectric,
• and if it’s not pyroelectric,
• then it’s not ferroelectric.