inha said:Do you mean piezoelectric crystals? I'm asking because those wouldn't need the strain to be nonuniform.
The electric polarization is a measure of the alignment of electric dipole moments in a material. When a strain gradient is applied to a material, it causes a change in the spacing and orientation of the atoms or molecules within the material. This change in spacing and orientation can induce a corresponding change in the electric dipole moments, resulting in an induced electric polarization.
Strain gradient-induced polarization is primarily observed in materials that have a non-centrosymmetric crystal structure, meaning they do not possess a center of symmetry. Examples of such materials include piezoelectric crystals, ferroelectric materials, and certain polymers.
The strength of the induced polarization is directly proportional to the magnitude of the applied strain gradient. This means that a larger strain gradient will result in a stronger induced polarization, while a smaller strain gradient will result in a weaker induced polarization.
Yes, the direction of the induced polarization can be controlled by the direction of the applied strain gradient. The induced polarization will align itself in the same direction as the strain gradient, resulting in a polarized material with a net dipole moment.
Strain gradient-induced polarization has numerous practical applications, particularly in the fields of mechanics, electronics, and material science. It is used in devices such as sensors, actuators, and transducers, and has also been studied for potential use in energy harvesting and storage. Additionally, the phenomenon has implications for understanding and controlling the behavior of materials under stress, which can aid in the development of stronger, more durable materials.