Electro-optic characteristics of aqueous β-FeOOH particles

Electro-optic characteristics of optically interacting β-FeOOH particles

“…It was demonstrated for the highly dilute suspension of β-FeOOH [9] that particle orientation in the kilohertz frequency range is due to particle surface polarization and the effects are consistent with the Kerr theory. A steady value of the effects is obtained in the plateau region (2-5 kHz) preceding the relaxation interval.…”

“…Table 1 lists several samples chosen to demonstrate the results. Some of them (samples 1, 3,5,9) were obtained by direct dilution of the basic suspension in bidistilled water; others (samples 2, 4, 6, 10) were obtained by removal of additional ions through centrifugation to definite conductivity of the supernatant and consequent dilution; two (samples 7 and 8) were obtained by taking the supernatant after short-time centrifugation of samples 1 and 3, respectively. The pH of the samples remained in the interval 4-5.5, where the particles are positively charged.…”

“…In a previous paper [9] we presented a detailed investigation of a highly diluted system of the same object (independent scattering). The basic electro-optic parameters determined in the Kerr (kilohertz) frequency range were: saturation value of the effect α S (corresponding to complete particle orientation along the field), particle rotational relaxation time τ (determined by exponential fitting of the decay of the responses at saturation fields), relaxation frequency of particle electric polarizability ν γ , relative variation of polarizability value γ on variation of the ionic content of the medium; and in the low-frequency (hertz) range: particle rotational relaxation frequency ν p (related to particle rotational diffusion coefficient) and phase shift of the responses at this frequency (related to the mechanism of particle orientation), characteristic field intensity curves as a measure of the slow electrokinetic effect.…”

Single-crystal star-like arrayed particles of hematite: Synthesis, formation mechanism and magnetic properties

“…As one of the most popular multifunctional materials, iron oxides have attracted great attention because of their interesting catalytic [7], electrical [8] and magnetic [9] properties, and various applications in such fields as sorbents [10], coatings [11], ion exchangers [12], gas sensors [11], electro-optic materials [13], and magnetic resonance imaging (MRI) [14]. In order to improve their properties, which are sensitively dependent on their sizes and morphologies, great effort has been devoted to control their sizes and morphologies.…”

Hydrothermal synthesis and characterization of α-FeOOH and α-Fe2O3 uniform nanocrystallines

“…such as electro-optic materials [10], sorbents [11], pigments [12], ion exchangers [13], and magnetic resonance imaging (MRI) [14], particularly in the field of catalysis [15]. Amongst the readily available carbon monoxide oxidation catalysts, iron oxide-based materials have been found to be especially attractive candidates as cheap and efficient catalysts [16].…”