Improving Magnetooptical Faraday Effect of maghemite/silica nanocomposites

Garcı́a, R.; Ramírez‐del‐Solar, M.; González-Leal, J.M.; Blanco, E.; Domí­nguez, Manuel

doi:10.1016/j.matchemphys.2014.12.049

Cited by 6 publications

(3 citation statements)

References 28 publications

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“…The NP/BCP composites discussed above exhibited both relatively high value of V and FOM, indicating excellent MO response and transparency. For instance, the Verdet constants of most NP/BCP composites at 845 nm were 10 times larger than those of composites made by sol-gel methods, which provided a maximum V ~4000-5000 °/T-m near 680-780 nm [37,44]. The maxima of FOM value of the 9.3 nm composite was as high as ~-27 °/T at 845 nm, 1.5 times higher than that of BiYIG single crystal at 760 nm [29].…”

Section: Verdet Constant Measurement Of Np/bcp Compositesmentioning

confidence: 99%

“…Various systems including MNPs and silica sol-gel porous matrix blends [36,37,[42][43][44], plasmonic enhanced shell MNPs [38,39,[45][46][47][48], and homopolymer stabilized core-shell MNP composites [34,35,[49][50][51] have been studied to understand both their scattering mechanisms and MO performance. Despite the high Verdet constants achieved in some of these composites, the resulting scattering from porous matrices produced by sol-gel methods [36,37,42] or aggregation of large NPs at higher concentrations [34,50] still limit the FR application of these materials at realistic length scales.…”

Section: Introductionmentioning

confidence: 99%

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Improving Faraday rotation performance with block copolymer and FePt nanoparticle magneto-optical composite

Miles¹,

Gai²,

Gangopadhyay³

et al. 2017

Opt. Mater. Express

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Magneto-optical (MO) composites with excellent Faraday rotation (FR) response were fabricated using iron platinum (FePt) nanoparticles (NPs) and polystyrene-block-poly (2-vinyl pyridine) (PS-b-P2VP) block copolymers (BCPs). Gallic acid functionalized FePt NPs with average core diameters (dcore) of 1.9, 4.9, 5.7 and 9.3 nm have been selectively incorporated into a P2VP domain through hydrogen bonding interactions. The use of copolymer templates to selectively arrange the magnetic NPs guaranteed high MO performance with little trade-off in terms of scattering loss, providing a simple strategy to prepare functional materials for MO applications. As a result, Verdet constants of a 10 wt % loaded 4.9 nm FePt NP composite reached absolute magnitudes as high as ~-6 × 10 4 °/T-m at 845 nm, as determined by FR measurements at room temperature. At the same time, the MO figure-of-merit was as large as −25 °/T in these composites, indicating both excellent MO performance and transparency. The dependence of the nanocomposite FR properties on particle diameter, loading (from 0.1 wt % to 10 wt %) and composite nanostructure were systematically investigated at four infrared wavelengths (845, 980, 1310 and 1550 nm Herranz, "Magnetophotonic response of three-dimensional opals," ACS Nano 5(4), 2957-2963 (2011). 12. J. C. Suits, "Faraday and Kerr effects in magnetic compounds," IEEE Trans. Magn. 8(1), 95-105 (1972 219-223 (1992) 3771-3774 (2015). 67. D. P. Song, C. Li, N. S. Colella, W. Xie, S. Li, X. Lu, S. Gido, J. H. Lee, and J. J. Watkins, "Large-volume selforganization of polymer/nanoparticle hybrids with millimeter-scale grain sizes using brush block copolymers," J.

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Section: Verdet Constant Measurement Of Np/bcp Compositesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improving Faraday rotation performance with block copolymer and FePt nanoparticle magneto-optical composite

Miles¹,

Gai²,

Gangopadhyay³

et al. 2017

Opt. Mater. Express

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“… − Garcia et al achieved one of the highest Verdet constants of a nanocomposite-glass material by incorporating maghemite magnetic nanoparticles into a sol–gel silica matrix (Figure ). The measured Verdet constant for the final material was 1.1 × 10 5 °/T·m at 780 nm but unfortunately suffered from poor transmission at this wavelength. Masood and co-workers explored a unique metallic glassy alloy system with Verdet constants of ∼2.94 and ∼4.9 × 10 7 °/T·m for Fe–B–Nb and Fe–B–Nb–Y metallic glassy alloys, respectively .…”

Section: Hard Materials For Magneto-opticsmentioning

confidence: 97%

High Verdet Constant Materials for Magneto-Optical Faraday Rotation: A Review

2022

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The Faraday effect is a magneto-optical (MO) phenomenon by which the polarization direction of linearly polarized light is rotated when passing through a transparent material with the application of a magnetic field along the direction of light propagation. The magnitude of the angle by which light is rotated at specific wavelengths, temperatures, and applied magnetic fields is directly proportional to the Verdet constant, which is an intrinsic bulk property of an optically transparent material. A high Verdet constant is desired for MO applications such as optical isolators, sensors, or modulators to reduce the path length required to obtain large optical rotation with modest magnetic fields to enable device miniaturization and overall cost reduction. MO material development has been ongoing for nearly the past two centuries, from which a wide range of materials have emerged. Herein, we review the development of high Verdet constant MO materials across many material classes, with an emphasis on recent developments of higher Verdet constant polymeric and polymer-nanocomposite materials. Inorganic materials have primarily been used for Faraday rotation systems which initially focused on the use of amorphous glasses and has since expanded into MO active crystals, ceramics, ferrofluids, organic small molecules, synthetic polymers, and polymer–nanoparticle nanocomposites. Although the most widely used materials for MO applications, hard matter based on inorganic materials typically possess Verdet constants on the order of 103–104 °/T·m at room temperature when measured in the visible and NIR ranges. More recent work has focused on using soft matter alternatives composed of organic small molecules, polymers, and polymer–nanoparticle nanocomposites which afford higher Verdet constants ranging from 104 to 106 °/T·m at room temperature. The current Review aims to discuss inorganic, organic, and hybrid high Verdet constant materials, which has been previously complicated by nonuniformity in the units and sampling conditions used for these MO measurements.

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