Doping the nematic liquid crystal 5CB with milled BaTiO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>3</mml:mn></mml:msub></mml:math>nanoparticles

Lorenz, Alexander; Zimmermann, Natalie; Kumar, Satyendra; Evans, Dean R.; Cook, Gary; Kitzerow, Heinz‐S.

doi:10.1103/physreve.86.051704

Cited by 33 publications

(17 citation statements)

References 24 publications

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“…6,[14][15][16][17][18][19][20][21][22] In addition to the size, the nanoparticle surface properties are also crucial for the manifestation of a well dispersed medium. Surface modification of NPs has been mainly been employed to achieve long-term stability of NPs in the LC medium and to smoothen director distortions around NPs, 23 thus reducing the cost of elastic energy.…”

Section: Reznikov Et Al Have Shown That a Low Concentration Of Ferromentioning

confidence: 99%

A comparison between size dependent paraelectric and ferroelectric BaTiO3 nanoparticle doped nematic and ferroelectric liquid crystals

Al-Zangana

Turner

Dierking

2017

Journal of Applied Physics

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The electro-optic and dielectric properties of barium titanate, BaTiO 3 , nanoparticle (NP) doped nematic and ferroelectric liquid crystal materials were examined with respect to different size and concentration of the NPs. Smaller size paraelectric NPs (≈80nm) are compared to larger, ferroelectric NPs (≈240nm). It is found that for concentrations larger than 0.5vol% the ferroelectric NPs exhibit an increasing effect on the electro-optic response of the nematic liquid crystal, which is demonstrated by the enhancement of the dielectric anisotropy. This could be induced by the coupling of the electrical dipole moments in the spherical NPs with the LC director field. The electro-optical properties of the SmC* phase, like tilt angle Θ, switching time and spontaneous polarisation are found to be independent of the concentration and size of the NPs. The rotational viscosity calculated from response times, polarization reversal current and dielectric properties is comparable for all three methods employed and practically independent of particle concentration and size. The relaxation frequency of the Goldstone mode is higher in the ferroelectric NPs suspensions of 2.0vol% as compared to the smaller paraelectric NPs.

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Section: Reznikov Et Al Have Shown That a Low Concentration Of Ferromentioning

confidence: 99%

A comparison between size dependent paraelectric and ferroelectric BaTiO3 nanoparticle doped nematic and ferroelectric liquid crystals

Al-Zangana

Turner

Dierking

2017

Journal of Applied Physics

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“…For simplicity the intrinsic anisotropy of TiO 2 was neglected. The lattice constant was taken equal to the larger (average) intermolecular distance in the two materials = ( ) a 2 nm [40,41]. In a possible experiment, the director of the liquid crystal can be anchored by a rubbed polymer layer [18,42,43], such that the preferred molecular orientation is parallel to the interface a p » ( ) 2 (see figure 9).…”

Section: Nematic Fluidsmentioning

confidence: 99%

Single-interface Casimir torque

Morgado

Silveirinha

2016

New J. Phys.

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A different type of Casimir-type interaction is theoretically predicted: a single-interface torque at a junction of an anisotropic material and a vacuum or another material system. The torque acts to reorient the polarizable microscopic units of the involved materials near the interface, and thus to change the internal structure of the materials. The single-interface torque depends on the zero-point energy of the interface localized and extended modes. Our theory demonstrates that the singleinterface torque is essential to understand the Casimir physics of material systems with anisotropic elements and may influence the orientation of the director of nematic liquid crystals. IntroductionCasimir-Lifshitz interactions [1-3] are the most paradigmatic example of quantum effects on the macro scale, and result from the confinement of the quantum-mechanical zero-point fluctuations of the electromagnetic field. Until recently, the study of quantum fluctuation-induced electromagnetic interactions was only of pure theoretical interest. Nevertheless, with the rapid development of micro-and nano-electromechanical systems (MEMS and NEMS) and its great impact in different areas [4,5], the research of Casimir-Lifshitz interactions has become of great practical importance as well. If, on one hand, Casimir interaction phenomena may lead to potentially undesired effects such as 'stiction' [6,7], on the other hand, they may open new and exciting possibilities in the field of micro and nanomechanics [4,[8][9][10][11].The study of Casimir-Lifshitz phenomena was pioneered by Casimir for more than 60 years ago [1]. In his seminal work, Casimir showed that as a result of the electromagnetic field quantum fluctuations, two parallel perfectly conducting plates standing in a vacuum may experience an attractive force pushing the plates toward each other. Following Casimir's prediction, Lifshitz, Dzyaloshinskii, and Pitaevskii extended the theory to the more general case of realistic isotropic dielectric plates, including non-ideal metals [2, 3]. Some years later, this theory was further generalized to anisotropic dielectric plates [12,13]. Interestingly, it was shown that the anisotropy may lead to the emergence of qualitatively different phenomena. It was demonstrated that a pair of parallel anisotropic uniaxial plates-with in-plane optical anisotropy and misaligned optical axes-separated by an isotropic dielectric, may experience a mechanical torque, designated as Casimir torque, that spontaneously forces the rotation of the plates towards the minimum energy position. The Casimir torque in this kind of systems was further investigated in [14][15][16][17][18]. In particular, numerical calculations of the torque were provided in [14][15][16]18], and possible experiments to measure the Casimir torque were proposed in [14,[16][17][18].With the emergence of metamaterials and their intriguing electromagnetic properties, the study of the Casimir-Lifshitz interactions has also been extended to systems with complex structural nanoscopic unities [1...

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“…Doping with nanoparticles can change the performance characteristics of LCs, such as electro-optic and dielectric properties, memory effect, and phase behavior. Various types of nanoparticles such as metallic [9], semiconducting [10], ferroelectric [11,12], carbon nano-tubes [13,14], dielectric and insulating [15][16][17][18][19] have been developed in recent years to realize LC nanocolloids. Several reports [20][21][22] have shown that doping of a nematic LC with small amounts of nanoparticles affects the properties of nematic LC such as the decrease of threshold and switching voltages, and switching time of the device.…”

Section: Introductionmentioning

confidence: 99%