Study of magnetite nanoparticles embedded in lyotropic liquid crystals

Arantes, Fabiana R.; Neto, A. M. Figueiredo; Cornejo, D.R.

doi:10.1016/j.phpro.2010.11.002

Cited by 6 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Taking into consideration that in the middle of the layer the deviation of the director from the axis of easy orientation is maximal, i.e., ϕ ′ = 0 at z = 0, the first integral of eqn (13) takes the form…”

Section: Orientational Equilibrium Equationsmentioning

confidence: 99%

“…In recent years there have been many experimental [11][12][13][14][15][16] and theoretical [17][18][19] works on the physical properties of magnetic suspensions based on liquid crystals and the peculiarities of their behavior in external fields. A detailed review of the history of research, classification, the most interesting experimental and theoretical results, as well as numerous applications of liquid-crystalline nanocolloids can be found in Ref.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interplay between dipole and quadrupole modes of field influence in liquid-crystalline suspensions of ferromagnetic particles

Makarov

Zakhlevnykh

2012

Soft Matter

View full text Add to dashboard Cite

In the framework of continuum theory we study orientational transitions induced by electric and magnetic fields in ferronematics, i.e., in liquid-crystalline suspensions of ferromagnetic particles. We have shown that in a certain electric field range the magnetic field can induce a sequence of re-entrant orientational transitions in ferronematic layer: nonuniform phase -uniform phasenonuniform phase. This phenomenon is caused by the interplay between the dipole (ferromagnetic) and quadrupole (dielectric and diamagnetic) mechanisms of the field influence on a ferronematic structure. We have found that these re-entrant Freedericksz transitions exhibit tricritical behavior, i.e., they can be of the first or the second order. The character of the transitions depends on a degree of redistribution of magnetic admixture in the sample exposed to uniform magnetic field (magnetic segregation). We demonstrate how electric and magnetic fields can change the order of orientational transitions in ferronematics. We show that electric Freedericksz transitions in ferronematics subjected to magnetic field have no re-entrant nature. Tricritical segregation parameters for the transitions induced by electric or magnetic fields are obtained analytically. We demonstrate the re-entrant behavior of ferronematic by numerical simulations of the magnetization and optical phase lag.

show abstract

Section: Orientational Equilibrium Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Interplay between dipole and quadrupole modes of field influence in liquid-crystalline suspensions of ferromagnetic particles

Makarov

Zakhlevnykh

2012

Soft Matter

View full text Add to dashboard Cite

show abstract

“…Ferronematic liquid crystals are artificial soft condensed matters, thereby actual research problems include synthesis, experimental and theoretical study of their physical properties and behavior in external fields. In the last few years an increased interest in these materials have been seen from both experimenters [3][4][5][6][7][8] and theoreticians [9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Reentrant Phase Transitions in Ferronematic Liquid Crystals

Makarov

Zakhlevnykh

2012

Molecular Crystals and Liquid Crystals

View full text Add to dashboard Cite

Within the continuum theory we study the influence of codirectional electric and magnetic fields on the orientational structure of a ferronematic layer taking into account the segregation effects. Recently in [Phys. Rev. E 81, 051710 (2010)] the tricritical behavior of the magnetic Freedericksz transition in ferronematics has been theoretically predicted. This paper shows that an external electric field can change the character of this transition. We find reentrant Freedericksz transitions in ferronematic liquid crystals subjected to the electric and magnetic fields. These transitions can be either first-or second-order ones. We derive the analytical expression for the width of the area of the reentrant orientational transitions.

show abstract