spontaneous polarization

spontaneous polarization

[spän′tā·nē·əs ‚pō·lə·rə′zā·shən]
(electricity)
Electric polarization that a substance possesses in the absence of an external electric field.
References in periodicals archive ?
Ferroelectric Materials mostly applicable in dielectric, pyro-electric, piezoelectric and others that offers dielectric properties, spontaneous polarization, spontaneous reversible polarization and provide output.
Summary: TEHRAN (FNA)- Researchers describe the first observation of a native ferroelectric metal: a native metal with bistable and electrically switchable spontaneous polarization states -- the hallmark of ferroelectricity.
Deformation, mainly determined by polarization square, can be used for the assessment of the macroscopic spontaneous polarization of ferroelectrics and the mean square of polarization in relaxor ferroelectrics.
This disposition has been strikingly described by the French-American anthropologist Rene Girard: "Once his basic needs are satisfied (indeed sometimes even before), man is subject to intense desires, though he may not know precisely for what." Via mimetic theory, Roberto Farneti (Assistant Professor of Politics, School of Economics and Management, Free University of Bozen-Bolzano, Italy) highlights phenomena that political scientists have consistently failed to notice, such as reciprocal imitation as the fundamental cause of human discord, the mechanisms of spontaneous polarization in human conflicts (i.e., the emergence of dyads or "doubles"), and the strange and ever-growing resemblance of the mimetic rivals, which is precisely what pushes them to annihilate each other.
Urbanc and Zeks [11] suggested that the spontaneous polarization (Ps) induced by a 'Type II' chiral dopant is influenced by steric interactions with the surroundings of host molecules that affects the rotational distribution of the core transverse dipole moment - with respect to the polar axis of the SmC phase [10].
It has been established that the spontaneous polarization, valence band offset, and quantum confinement effect were three key effects in the heterocrystalline superlattice which should be considered [8].
The local geometry around the critical points of the free energy functional is represented by a certain catastrophe function, which is determined by the elastic, surface, spontaneous polarization and dielectric free energy densities.
Ferroelectricity is an electrical phenomenon of ferroelectric materials may exhibit a spontaneous polarization which the direction of the polarization can be switched by the application of an external electric field.
where A is the area of the cell, [epsilon] is the dielectric constant of the ferroelectric materials, [E.sub.a] is the applied electric field, [t.sub.s] is the switching time, i is the switching current, [[epsilon].sub.0] is the permittivity of free space, and [P.sub.s] is the spontaneous polarization of the ferroelectric material.
In the study, the researchers have demonstrated for the first time a giant intrinsic electroresistance in conventional ferroelectric films, where flipping of the spontaneous polarization increased conductance by up to 50,000 percent.
By applying an electrical poling field, typically 2 V/cm, across the crystal boule at an elevated temperature (1140 [degrees] C), and cooling under its influence, the ions can be made to displace along the direction of the electric field, thus inducing a well-ordered degree of spontaneous polarization (single ferroelectric domains), which is maintained at room temperature.
The FLC's layered, chiral structure and spontaneous polarization capability make device fabrication more complex than in conventional nematic or cholesteric LC materials, says Marshall.

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