Piezoelectricity vs Ferroelectricity: Key Differences Explained

This article delves into the comparison between Piezoelectricity and Ferroelectricity, highlighting their distinctions.

Piezoelectricity Vs Ferroelectricity

Piezoelectricity

Definition: Piezoelectricity refers to the generation of electricity through the application of pressure. More precisely, it’s the accumulation of electric charge in certain solid materials when they are subjected to mechanical stress.

These materials can include:

• Crystals
• Ceramics
• Biological matter (e.g., DNA, bone)

Figure 1 (implied from the text) demonstrates the effect of compression on a piezoelectric material.

Direct Piezoelectric Effect

In this scenario, the material generates an electric potential when mechanical stress is applied. When compression is exerted, the volume decreases, producing a voltage with the same polarity as the material. Conversely, when tension is applied, the volume increases, and a voltage with the opposite polarity is generated compared to the material.

Inverse Piezoelectric Effect

Here, when an electric field (E-field) is applied to the material, it either shortens or lengthens proportionally to the applied voltage.

Basic Equations for Piezoelectricity

The fundamental equations governing piezoelectricity are:

$P = D \times \text{Stress}$ … Equation-1

$E = \frac{\text{Strain}}{D}$ … Equation-2

Where:

• $P$ = Polarization
• $E$ = Generated Electric Field
• $D$ = Piezoelectric coefficient (in meters/volt)

Ferroelectricity

Definition: Ferroelectricity is a property exhibited by certain non-conducting crystals or dielectrics, characterized by spontaneous electric polarization.

This polarization is significant because it can be reversed by applying an appropriate electric field.

Figure 1 (implied from the text, likely the same figure as for Piezoelectricity) illustrates this phenomenon.