BIREFRINGENCE AND MAGNETO-OPTICAL PROPERTIES IN OLEIC ACID COATED Fe₃O₄ NANOPARTICLES: APPLICATION FOR OPTICAL SWITCH

Abstract

We report magneto-optical properties in a kerosene colloidal suspension of oleic acid coated Fe3O4 nanoparticles (~14 nm). The magnetic colloids (fluids) show birefringence under a magnetic field. Systematical studies of the on–off switch times upon application of the on–off magnetic field with varied experimental parameters indicate that the switch response time depends strongly on the strength of the magnetic field and the concentration of the magnetic nanoparticles in the fluid. The data can be explained in terms of the formation of magnetic nanoparticle chains under a magnetic field. The important magneto-optical properties of the magnetic fluids allow us to design a tunable optical switch.

Magnetization enhancement in magnetite nanoparticles capped with alginic acid

“…The best fit of eq. ( 1) to the data presented in the histogram is obtained for the median size 〈D〉=20.6(1) nm and standard deviation σ=0.144 (6). Crystallographic structure of the Fe 3 O 4 nanoparticles was analyzed by means of HRTEM and a representative image is presented in Fig.…”

“…Magnetite Fe 3 O 4 is one of the best and most preferred materials to combine with various polymers because of unique physical properties, like ferrimagnetic ordering, large magnetic moment, relatively high conductivity and high ratio of spin polarization. These features make magnetite a highly desired material for future applications in medicine [1], spintronics [2], electronic and optoelectronic devices [3][4][5][6], sensors [7] and for magnetic data storage [8].…”

Study of Light Polarization by Ferrofluid Film Using Jones Calculus

“…Certain phenomena that simultaneously involve optics and magnetism are known as magneto-optical phenomena and can be observed with a device known as Ferrocell, in which one can see several interesting effects, such as Horocycles of light [3] or light polarization [4][5][6][7][8]. Left and right polarization of light can propagate at different speeds in ferrofluids leading to birefringence and dichroism and making possible some technological applications such as tunable gratings, optical modulators, and sensors [4][5][6][7][8][9][10][11][12][13][14][15][16][17], which explains the increased interest in understanding the features behind this system in matters such as the polarization of light [18][19][20][21]. In Figure 1, we show the image of light that propagated through a ferrofluid that was altered by the presence of a magnetic field in a device known as a Ferrocell.…”

Magnetic Field Sensing Based on Magnetic-Fluid-Clad Fiber-Optic Structure With Up-Tapered Joints

“…So far, versatile properties have been demonstrated (e.g., tunable refractive index (RI) [2], [3], magneto-volume variation [4] and magneto-dielectric anisotropy [5]). Many potential optical and sensing applications based on MFs have been proposed, such as optical switches [6], optical gratings [7], [8], tunable optical capacitors [9], modulators [10], [11], tunable slow-light [12], and magnetic field sensors [2]- [4], [13]- [21]. Due to the fluidity of MFs, they can be easily integrated with fibers.…”