Super-coercive electric field hysteresis in ferroelectric plastic crystal tetramethylammonium bromotrichloroferrate(iii)

Abstract

Ionic plastic crystals are part of an emerging class of hybrid organic–inorganic ferroelectrics. Their super-coercive electric field hysteresis bares the signatures of ferroelectric switching, including interesting contributions from defects.

Unusual Properties of Hydrogen-Bonded Ferroelectrics: The Case of Cobalt Formate

“…Indeed, in agreement with our computational predictions as well as Ref. [31] no hysteresis loops were observed for this field. The finding provides experimental support for our computational prediction of a large intrinsic coercive field.…”

“…Second, if the applied field is lower than the coercive field for a given temperature the ferroelectric loops cannot occur (or will be highly distorted). Indeed it was observed experimentally, that below 40 kV=cm no hysteresis loops occur [31]. We can also see that increase in frequencies causes an increase in the coercive field, that is supercoercivity, reported experimentally [31].…”

“…Indeed it was observed experimentally, that below 40 kV=cm no hysteresis loops occur [31]. We can also see that increase in frequencies causes an increase in the coercive field, that is supercoercivity, reported experimentally [31]. Third, the intrinsic coercive field is very large.…”

“…The smallest field to allow for the transition is the coercive field and can be estimated as E c ¼ ½ΔU − k B T lnð2ν=ν E Þ=jPjV. The expression predicts that in agreement with experiment [31] the coercive field exhibits frequency dependence, that is, it increases with the frequency [31]. To incorporate temperature dependence into ΔU we recall that within the Landau theory of phase transitions some coefficients of the energy expansion UðPÞ are taken to be linearly dependent on temperature.…”

Statics and dynamics of ferroelectric domains in molecular multiaxial ferroelectric (Me3NOH)2[KCo(CN)6]

“…[8][9][10][11] Early studies have shown that molecular ferroelectrics are uniaxial, [12][13][14][15][16][17][18][19] so that their ferroelectric functionality was restricted in a single-crystal form because the polarization could only be switched along the single polarization axis. With the development of targeted design strategies, [20][21][22][23] multiaxial ferroelectricity was further discovered in molecular systems, such as hybrid perovskites, [24][25][26] simple salts, [27][28][29][30][31][32] and plastic crystals, [33][34][35] in which several ferroelectric axes allow for arbitrarily directed polarization to orient along the electric field, hence rendering ferroelectric properties in a polycrystalline form. Moreover, due to several advantages such as light weight, mechanical flexibility, low acoustical impedance, and easy processability, the multiaxial molecular ferroelectrics are expected to replace the widely used inorganic oxides in the next-generation flexible electronics.…”